query works for string data type columns with missing values but not for boolean indexing
#### Code Sample, a copy-pastable example if possible

```python
>>> df = pd.DataFrame({'a': ['asdf', None]}, dtype='string')
>>> df.query('a == "asdf"') # works
>>> df[df['a'] == 'asdf'] # fails
>>> df.query('a <= "asdf"') # fails
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-24-1d73f7d1a2fe> in <module>
----> 1 df[df['a'] == 'asdf']

~/Documents/Code Practice/pandas-dev/pandas/pandas/core/frame.py in __getitem__(self, key)
   2784 
   2785         # Do we have a (boolean) 1d indexer?
-> 2786         if com.is_bool_indexer(key):
   2787             return self._getitem_bool_array(key)
   2788 

~/Documents/Code Practice/pandas-dev/pandas/pandas/core/common.py in is_bool_indexer(key)
    132             if is_extension_array_dtype(key.dtype):
    133                 if np.any(key.isna()):
--> 134                     raise ValueError(na_msg)
    135             return True
    136     elif isinstance(key, list):

ValueError: cannot mask with array containing NA / NaN values
```
#### Problem description

This is a specific bug found from discussion in #31503. The new string data type should fail for any `query` call where there are missing values in the evaluated condition. It correctly fails for boolean indexing and for inequality conditions in `query`

#### Expected Output

`df.query('a == "asdf"')` should fail

#### Output of ``pd.show_versions()``

<details>

INSTALLED VERSIONS
------------------
commit           : None
python           : 3.8.1.final.0
python-bits      : 64
OS               : Darwin
OS-release       : 19.2.0
machine          : x86_64
processor        : i386
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 0+untagged.1.gce8af21.dirty
numpy            : 1.18.1
pytz             : 2019.3
dateutil         : 2.8.1
pip              : 20.0.2
setuptools       : 45.1.0.post20200127
Cython           : 0.29.14
pytest           : None
hypothesis       : None
sphinx           : None
blosc            : None
feather          : None
xlsxwriter       : None
lxml.etree       : 4.5.0
html5lib         : None
pymysql          : None
psycopg2         : None
jinja2           : 2.10.3
IPython          : 7.11.1
pandas_datareader: None
bs4              : None
bottleneck       : None
fastparquet      : None
gcsfs            : None
lxml.etree       : 4.5.0
matplotlib       : 3.1.1
numexpr          : None
odfpy            : None
openpyxl         : None
pandas_gbq       : None
pyarrow          : None
pytables         : None
pytest           : None
pyxlsb           : None
s3fs             : None
scipy            : 1.3.1
sqlalchemy       : 1.3.13
tables           : None
tabulate         : 0.8.3
xarray           : None
xlrd             : None
xlwt             : None
xlsxwriter       : None
numba            : None

</details>
