is_bool_dtype for ExtensionArrays
Closes #22326
Closes #22665 

Two commits:  https://github.com/pandas-dev/pandas/commit/fe3500248dec1b21469e94e054f636dc7707fae0 partially implements an Arrow-backed ExtensionArray. We need this as we don't currently have any boolean-values EAs.

https://github.com/pandas-dev/pandas/commit/04029ac94d1e53fbec18264beabccb49c1e002b1 has the fix for the bug.