[django-filter] Improve constructor param types and add missing __all__

[intgr]

This is all I found that could be improved in #14540. FYI @huynguyengl99

• Added __init__ params that are inherited from parent classes. Reduced usage of loosely typed *args, **kwargs.
• Removed __init__ method type hints from classes whose parameters are same as parent class -- to avoid duplicating them.
• Added __all__ to django_filters/rest_framework/__init__.pyi -- the imports in this file are clearly meant as re-export, but without __all__ I believe type-checkers don't allow using them.

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉

[donBarbos]

Just a quick note — it’s generally a good practice to add a comment for each use of Any. If you’re unsure whether it should be Any, it might be better to use Incomplete instead.
It’s also important to ensure that the stubtests are passing. And regarding __all__ in type stubs - it should simply reflect the real __all__ in the source code, and it’s worth including it in the stubs if it exists in the source.

[srittau]

LGTM, but one question below.

[srittau]

Considering that we require django-stubs, can't we just import those from there?

[intgr]

I tried, but IIRC received a mypy error about importing non-public members. Will try again and report back.

[intgr]

Thanks, I'll find the time some day to fix CI errors and resolve review comments.

__all__ in type stubs - it should simply reflect the real __all__ in the source code

👍 I will convert them to import X as X imports.