arrow

ARROW-15839: [C++][Python] Accept validity bitmap in ListArray.from_arrays (#13894)

Will close [ARROW-15839](https://issues.apache.org/jira/browse/ARROW-15839)

This will allow proper nulls in place of what is presently empty lists (on top level) when no mask is passed.

```python
import pyarrow as pa

arr = pa.array([None, [0]])
reconstructed_arr = pa.ListArray.from_arrays(arr.offsets, arr.values, mask=arr.is_null())
print(reconstructed_arr.to_pylist())
# [None, [0]] 
# Currently it doesn't accept `mask` and results in `[[], [0]]` unless explicit offsets set
```

There was also discussion with @jorisvandenbossche about renaming the added `null_bitmap` to `validity_bitmap`; but this will deviate from [existing `null_bitmap` use in the same area of code](https://github.com/apache/arrow/blob/d880d7517a33f2ac8ff259cad711bc210fd570c5/cpp/src/arrow/array/array_nested.h#L113). Should I change those names now or in a later PR/issue to standardize the `null_bitmap` / `validity_buf` naming?

Lead-authored-by: Miles Granger <miles59923@gmail.com>
Co-authored-by: Antoine Pitrou <pitrou@free.fr>
Signed-off-by: Antoine Pitrou <antoine@python.org>