[Python] Gradually add types checks to Arrow

[rok]

This proposes adding type annotation to pyarrow by adopting pyarrow-stubs into pyarrow. To do so we copy a subset of pyarrow-subs's stubfiles into pyarrow tree. We then add annotation checks for some stubsfiles and some test files and make sure checks pass. Annotation checks should be expanded until all (or most) project files are covered in future work.

PR introduces:

1. adds pyarrow-stubs into arrow/python/pyarrow/
2. fixes pyarrow-stubs to pass mypy and pyright check
3. adds mypy and pyright check to CI (crudely)
4. adds a tool (update_stub_docstrings.py) to keep annotation docstrings in sync with source docstrings
5. adds docstring sync check to CI (crudely)