Missing Imports
in setup.cfg we currently have

```
[mypy]
ignore_missing_imports=True
```

mypy states "We recommend using this approach only as a last resort: it’s equivalent to adding a # type: ignore to all unresolved imports in your codebase." https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports

the number of instances of missing imports resolving to Any is already significant..
```
$ mypy pandas --disallow-any-unimported
pandas\util\_test_decorators.py:106: error: Return type becomes "Any" due to an unfollowed import
pandas\util\_test_decorators.py:120: error: Return type becomes "Any" due to an unfollowed import
pandas\_typing.py:19: error: Constraint 5 becomes "Any" due to an unfollowed import
pandas\_typing.py:22: error: Constraint 2 becomes "Any" due to an unfollowed import
pandas\_typing.py:23: error: Constraint 1 becomes "Any" due to an unfollowed import
pandas\_typing.py:23: error: Constraint 2 becomes "Any" due to an unfollowed import
pandas\_typing.py:23: error: Constraint 3 becomes "Any" due to an unfollowed import
pandas\io\formats\printing.py:252: error: Base type BaseFormatter becomes "Any" due to an unfollowed import
pandas\core\dtypes\dtypes.py:653: error: Type of variable becomes "Type[Any]" due to an unfollowed import
pandas\core\dtypes\dtypes.py:812: error: Type of variable becomes "Type[Any]" due to an unfollowed import
pandas\core\dtypes\common.py:144: error: Return type becomes "Any" due to an unfollowed import
pandas\core\dtypes\common.py:144: error: Argument 1 to "ensure_int_or_float" becomes "Any" due to an unfollowed import
pandas\core\dtypes\common.py:181: error: Argument 1 to "ensure_python_int" becomes "Union[int, Any]" due to an unfollowed import
pandas\core\indexers.py:39: error: Argument 2 to "is_empty_indexer" becomes "Any" due to an unfollowed import
pandas\core\indexers.py:115: error: Argument 1 to "validate_indices" becomes "Any" due to an unfollowed import
pandas\core\dtypes\cast.py:765: error: Argument 1 to "maybe_convert_objects" becomes "Any" due to an unfollowed import
pandas\core\dtypes\cast.py:814: error: Argument 1 to "soft_convert_objects" becomes "Any" due to an unfollowed import
pandas\core\nanops.py:194: error: Return type becomes "Optional[Any]" due to an unfollowed import
pandas\core\nanops.py:194: error: Argument 1 to "_maybe_get_mask" becomes "Any" due to an unfollowed import
pandas\core\nanops.py:194: error: Argument 3 to "_maybe_get_mask" becomes "Optional[Any]" due to an unfollowed import
pandas\core\nanops.py:237: error: Return type becomes "Tuple[Any, Optional[Any], Any, Any, Any]" due to an unfollowed import
pandas\core\nanops.py:237: error: Argument 1 to "_get_values" becomes "Any" due to an unfollowed import
pandas\core\nanops.py:237: error: Argument 5 to "_get_values" becomes "Optional[Any]" due to an unfollowed import
pandas\core\nanops.py:634: error: Return type becomes "Tuple[Union[int, Any], Union[int, Any]]" due to an unfollowed import
pandas\core\nanops.py:634: error: Argument 2 to "_get_counts_nanvar" becomes "Optional[Any]" due to an unfollowed import
pandas\core\nanops.py:672: error: Type of variable becomes "Any" due to an unfollowed import
pandas\core\nanops.py:1117: error: Return type becomes "Union[Any, int]" due to an unfollowed import
pandas\core\nanops.py:1117: error: Argument 1 to "_maybe_arg_null_out" becomes "Any" due to an unfollowed import
pandas\core\nanops.py:1117: error: Argument 3 to "_maybe_arg_null_out" becomes "Optional[Any]" due to an unfollowed import
pandas\core\nanops.py:1141: error: Return type becomes "Union[int, Any]" due to an unfollowed import
pandas\core\nanops.py:1141: error: Argument 2 to "_get_counts" becomes "Optional[Any]" due to an unfollowed import
pandas\core\nanops.py:1185: error: Return type becomes "Any" due to an unfollowed import
pandas\core\nanops.py:1185: error: Argument 1 to "_maybe_null_out" becomes "Any" due to an unfollowed import
pandas\core\nanops.py:1185: error: Argument 3 to "_maybe_null_out" becomes "Optional[Any]" due to an unfollowed import
pandas\core\construction.py:51: error: Return type becomes "Any" due to an unfollowed import
pandas\core\construction.py:51: error: Argument 2 to "array" becomes "Union[str, Any, ExtensionDtype, None]" due to an unfollowed import
pandas\core\tools\datetimes.py:71: error: Argument 1 to "should_cache" becomes "Union[List[Any], Tuple[Any, ...], Any, Any]" due to an unfollowed import
pandas\core\tools\datetimes.py:161: error: Return type becomes "Any" due to an unfollowed import
pandas\core\tools\datetimes.py:161: error: Argument 1 to "_box_as_indexlike" becomes "Any" due to an unfollowed import
pandas\core\tools\datetimes.py:191: error: Return type becomes "Union[Any, Any]" due to an unfollowed import
pandas\core\tools\datetimes.py:191: error: Argument 1 to "_convert_and_box_cache" becomes "Union[Any, List[Any], Tuple[Any, ...], Any, Any]" due to an unfollowed import
pandas\core\tools\datetimes.py:191: error: Argument 2 to "_convert_and_box_cache" becomes "Any" due to an unfollowed import
pandas\tseries\offsets.py:157: error: Base type BaseOffset becomes "Any" due to an unfollowed import
pandas\tseries\offsets.py:2513: error: Base type _Tick becomes "Any" due to an unfollowed import
pandas\core\arrays\_ranges.py:15: error: Return type becomes "Tuple[Any, str]" due to an unfollowed import
pandas\core\arrays\_ranges.py:15: error: Argument 1 to "generate_regular_range" becomes "Any" due to an unfollowed import
pandas\core\arrays\_ranges.py:15: error: Argument 2 to "generate_regular_range" becomes "Any" due to an unfollowed import
pandas\core\ops\__init__.py:398: error: Argument 1 to "should_extension_dispatch" becomes "Any" due to an unfollowed import
pandas\core\ops\__init__.py:1152: error: Argument 1 to "maybe_dispatch_ufunc_to_dunder_op" becomes "Any" due to an unfollowed import
pandas\core\ops\__init__.py:1152: error: Argument 4 to "maybe_dispatch_ufunc_to_dunder_op" becomes "Any" due to an unfollowed import
pandas\core\arrays\period.py:230: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\period.py:230: error: Argument 2 to "_from_sequence" becomes "Sequence[Optional[Any]]" due to an unfollowed import
pandas\core\arrays\period.py:301: error: Argument 2 to "_unbox_scalar" becomes "Union[Any, Any]" due to an unfollowed import
pandas\core\arrays\period.py:313: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\period.py:655: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\period.py:655: error: Argument 2 to "_addsub_int_array" becomes "Union[Any, Any, Any, Any]" due to an unfollowed import
pandas\core\arrays\period.py:833: error: Argument 1 to "period_array" becomes "Sequence[Optional[Any]]" due to an unfollowed import
pandas\core\arrays\datetimes.py:330: error: Type of variable becomes "Union[Any, DatetimeTZDtype]" due to an unfollowed import
pandas\core\arrays\datetimes.py:604: error: Return type becomes "Union[Any, DatetimeTZDtype]" due to an unfollowed import
pandas\core\arrays\base.py:267: error: Argument 2 to "__setitem__" becomes "Union[int, Any]" due to an unfollowed import
pandas\core\arrays\base.py:392: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\base.py:414: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\base.py:525: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\base.py:637: error: Return type becomes "Tuple[Any, Any]" due to an unfollowed import
pandas\core\arrays\base.py:661: error: Return type becomes "Tuple[Any, Any]" due to an unfollowed import
pandas\core\arrays\base.py:764: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\base.py:855: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\base.py:865: error: Return type becomes "Union[Any, Any]" due to an unfollowed import
pandas\core\arrays\base.py:936: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\base.py:956: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\base.py:956: error: Argument 2 to "_concat_same_type" becomes "Sequence[Any]" due to an unfollowed import
pandas\core\arrays\base.py:980: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\numpy_.py:89: error: Base type NDArrayOperatorsMixin becomes "Any" due to an unfollowed import
pandas\core\arrays\datetimelike.py:58: error: Type of variable becomes "Any" due to an unfollowed import
pandas\core\arrays\datetimelike.py:65: error: Return type becomes "Type[Any]" due to an unfollowed import
pandas\core\arrays\datetimelike.py:74: error: Return type becomes "Union[Any, Any, Any, Any]" due to an unfollowed import
pandas\core\arrays\datetimelike.py:96: error: Argument 2 to "_unbox_scalar" becomes "Union[Any, Any, Any, Any]" due to an unfollowed import
pandas\core\arrays\datetimelike.py:115: error: Argument 2 to "_check_compatible_with" becomes "Union[Any, Any, Any, Any]" due to an unfollowed import
pandas\core\arrays\datetimelike.py:348: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\datetimelike.py:453: error: Argument 3 to "__setitem__" becomes "Union[Any, Any, Sequence[Any]]" due to an unfollowed import
pandas\core\base.py:990: error: Return type becomes "Any" due to an unfollowed import
pandas\core\indexes\frozen.py:123: error: Base type ndarray becomes "Any" due to an unfollowed import
pandas\core\indexes\base.py:3871: error: Return type becomes "Union[ExtensionArray, Any, Any]" due to an unfollowed import
pandas\core\arrays\sparse.py:109: error: Argument 2 to "__init__" becomes "Union[str, Any, ExtensionDtype]" due to an unfollowed import
pandas\core\arrays\sparse.py:393: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\sparse.py:393: error: Argument 1 to "_get_fill" becomes "Any" due to an unfollowed import
pandas\core\arrays\sparse.py:417: error: Argument 1 to "_sparse_array_op" becomes "Any" due to an unfollowed import
pandas\core\arrays\sparse.py:417: error: Argument 2 to "_sparse_array_op" becomes "Any" due to an unfollowed import
pandas\core\arrays\sparse.py:706: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\sparse.py:706: error: Argument 2 to "_simple_new" becomes "Any" due to an unfollowed import
pandas\core\arrays\sparse.py:706: error: Argument 3 to "_simple_new" becomes "Any" due to an unfollowed import
pandas\core\arrays\interval.py:143: error: Base type IntervalMixin becomes "Any" due to an unfollowed import
pandas\core\arrays\integer.py:519: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\integer.py:576: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\categorical.py:479: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\categorical.py:502: error: Argument 2 to "astype" becomes "Union[str, Any, ExtensionDtype]" due to an unfollowed import
pandas\core\arrays\categorical.py:502: error: Return type becomes "Any" due to an unfollowed import
pandas\core\arrays\categorical.py:2652: error: Argument 1 to "_recode_for_categories" becomes "Any" due to an unfollowed import
pandas\core\internals\blocks.py:1858: error: Argument 3 to "shift" becomes "Any" due to an unfollowed import
pandas\core\indexes\multi.py:64: error: Base type BaseMultiIndexCodesEngine becomes "Any" due to an unfollowed import
pandas\core\indexes\multi.py:64: error: Base type UInt64Engine becomes "Any" due to an unfollowed import
pandas\core\indexes\multi.py:103: error: Base type BaseMultiIndexCodesEngine becomes "Any" due to an unfollowed import
pandas\core\indexes\multi.py:103: error: Base type ObjectEngine becomes "Any" due to an unfollowed import
pandas\core\indexes\category.py:525: error: Argument 2 to "get_value" becomes "Any" due to an unfollowed import
pandas\core\indexes\range.py:79: error: Type of variable becomes "Any" due to an unfollowed import
pandas\core\indexes\range.py:363: error: Argument 2 to "__contains__" becomes "Union[int, Any]" due to an unfollowed import
pandas\core\indexes\interval.py:201: error: Base type IntervalMixin becomes "Any" due to an unfollowed import
pandas\core\indexes\interval.py:629: error: Argument 2 to "_can_reindex" becomes "Any" due to an unfollowed import
pandas\core\indexes\interval.py:790: error: Return type becomes "Union[int, slice, Any]" due to an unfollowed import
pandas\core\indexes\interval.py:861: error: Return type becomes "Any" due to an unfollowed import
pandas\core\indexes\interval.py:861: error: Argument 2 to "get_indexer" becomes "Any" due to an unfollowed import
pandas\core\indexes\interval.py:931: error: Return type becomes "Tuple[Any, Any]" due to an unfollowed import
pandas\core\indexes\interval.py:931: error: Argument 2 to "get_indexer_non_unique" becomes "Any" due to an unfollowed import
pandas\core\indexes\interval.py:972: error: Return type becomes "Any" due to an unfollowed import
pandas\core\indexes\interval.py:972: error: Argument 2 to "get_indexer_for" becomes "Any" due to an unfollowed import
pandas\core\indexes\interval.py:989: error: Argument 2 to "get_value" becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:123: error: Base type ConversionInterface becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:150: error: Base type Formatter becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:193: error: Base type DateConverter becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:252: error: Base type DateConverter becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:325: error: Base type AutoDateFormatter becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:330: error: Base type AutoDateLocator becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:355: error: Base type DateLocator becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:936: error: Base type Locator becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:1030: error: Base type Formatter becomes "Any" due to an unfollowed import
pandas\plotting\_matplotlib\converter.py:1098: error: Base type Formatter becomes "Any" due to an unfollowed import
pandas\io\formats\format.py:1294: error: Return type becomes "Any" due to an unfollowed import
pandas\io\formats\format.py:1400: error: Argument 2 to "__init__" becomes "Union[Any, Series, DatetimeIndex, DatetimeArray]" due to an unfollowed import
pandas\io\formats\format.py:1457: error: Argument 1 to "format_percentiles" becomes "Union[Any, List[Union[int, float]], List[float], List[Union[str, float]]]" due to an unfollowed import
pandas\io\formats\format.py:1527: error: Argument 1 to "_is_dates_only" becomes "Union[Any, DatetimeArray, Index, DatetimeIndex]" due to an unfollowed import
pandas\io\formats\format.py:1548: error: Argument 1 to "_format_datetime64" becomes "Union[Any, Any]" due to an unfollowed import
pandas\io\formats\format.py:1548: error: Argument 2 to "_format_datetime64" becomes "Union[Any, tzutc, None]" due to an unfollowed import
pandas\io\formats\format.py:1565: error: Argument 1 to "_format_datetime64_dateonly" becomes "Union[Any, Any]" due to an unfollowed import
pandas\io\formats\format.py:1592: error: Argument 1 to "_get_format_datetime64_from_values" becomes "Union[Any, DatetimeArray, DatetimeIndex]" due to an unfollowed import
pandas\io\formats\format.py:1623: error: Argument 2 to "__init__" becomes "Union[Any, TimedeltaIndex]" due to an unfollowed import
pandas\io\formats\format.py:1641: error: Argument 1 to "_get_format_timedelta64" becomes "Union[Any, TimedeltaIndex, TimedeltaArray]" due to an unfollowed import
pandas\io\formats\format.py:1719: error: Argument 1 to "_trim_zeros_complex" becomes "Any" due to an unfollowed import
pandas\io\formats\format.py:1730: error: Argument 1 to "_trim_zeros_float" becomes "Union[Any, List[str]]" due to an unfollowed import
pandas\io\formats\format.py:1872: error: Argument 1 to "_binify" becomes "List[Any]" due to an unfollowed import
pandas\io\formats\format.py:1872: error: Argument 2 to "_binify" becomes "Union[Any, int]" due to an unfollowed import
pandas\core\indexing.py:102: error: Base type _NDFrameIndexerBase becomes "Any" due to an unfollowed import
pandas\core\indexing.py:650: error: Argument 3 to "_align_series" becomes "Any" due to an unfollowed import
pandas\core\indexing.py:742: error: Argument 3 to "_align_frame" becomes "Any" due to an unfollowed import
pandas\core\indexing.py:2162: error: Base type _NDFrameIndexerBase becomes "Any" due to an unfollowed import
pandas\core\indexing.py:2371: error: Return type becomes "Any" due to an unfollowed import
pandas\core\internals\managers.py:1874: error: Return type becomes "Union[Any, ExtensionDtype, None]" due to an unfollowed import
pandas\core\generic.py:164: error: Argument 5 to "__init__" becomes "Union[str, Any, ExtensionDtype, None]" due to an unfollowed import
pandas\core\frame.py:6535: error: Return type becomes "Union[Series, Any]" due to an unfollowed import
pandas\core\frame.py:6535: error: Argument 4 to "_gotitem" becomes "Union[Series, Any, None]" due to an unfollowed import
pandas\core\groupby\groupby.py:1087: error: Return type becomes "Tuple[Any, Type[Any]]" due to an unfollowed import
pandas\core\groupby\groupby.py:1087: error: Argument 1 to "objs_to_bool" becomes "Any" due to an unfollowed import
pandas\core\groupby\groupby.py:1095: error: Return type becomes "Any" due to an unfollowed import
pandas\core\groupby\groupby.py:1095: error: Argument 1 to "result_to_bool" becomes "Any" due to an unfollowed import
pandas\core\groupby\groupby.py:1879: error: Return type becomes "Tuple[Any, Optional[Type[Any]]]" due to an unfollowed import
pandas\core\groupby\groupby.py:1879: error: Argument 1 to "pre_processor" becomes "Any" due to an unfollowed import
pandas\core\groupby\groupby.py:1894: error: Return type becomes "Any" due to an unfollowed import
pandas\core\groupby\groupby.py:1894: error: Argument 1 to "post_processor" becomes "Any" due to an unfollowed import
pandas\io\packers.py:800: error: Base type _Packer becomes "Any" due to an unfollowed import
pandas\io\packers.py:820: error: Base type _Unpacker becomes "Any" due to an unfollowed import
pandas\core\window\rolling.py:209: error: Return type becomes "Optional[Any]" due to an unfollowed import
pandas\core\window\rolling.py:222: error: Return type becomes "Any" due to an unfollowed import
pandas\core\window\rolling.py:222: error: Argument 2 to "_prep_values" becomes "Optional[Any]" due to an unfollowed import
pandas\core\window\rolling.py:335: error: Return type becomes "Any" due to an unfollowed import
pandas\core\window\rolling.py:352: error: Argument 4 to "_get_roll_func" becomes "Any" due to an unfollowed import
pandas\core\window\rolling.py:788: error: Return type becomes "Any" due to an unfollowed import
pandas\core\window\rolling.py:844: error: Argument 4 to "_get_roll_func" becomes "Any" due to an unfollowed import
```

Ideas for keeping this manageable?

cc @WillAyd 