Add pyright for static type checking (#17744)
Related to #17301
Summary of the issue:
NVDA has no type checking for python.
Python is a dynamically typed language meaning typing issues can occur at runtime.
Static analysers like `mypy` or `pyright` can be used to avoid typing errors.
Description of user facing changes
None
Description of development approach
`pyright` was chosen over `mypy` for performance reasons.
Additionally, pyright has better pre-commit integration, and is built-in to VS Code, which is used by most NVDA developers.
We are far from compliant with static type checking, so most rules are currently disabled.
The intention is to fix compliance and turn on rules over time.
Various trivial typing fixes have occurred, particularly:
- removing unnecessary casts
- fixing type hints
- adding relevant type ignore comments
- removing redundant type ignore comments
- adding type stubs for `gettext` builtins and `_buildVersion` generated build vars
- remove duplicate imports
- adding `__all__` to mark export for private classes
- adding missing `match` cases
Testing strategy:
- [x] Smoke test NVDA
- [x] pyright passing
- [x] Automated testing passes
Known issues with pull request:
We are far from compliant with static type checking, so most rules are currently disabled.
The intention is to fix compliance and turn on rules over time.
