docs(stub files): remove the majority of stub files

[Catalyst4222]

About

This pull request removes nearly every .pyi file

The pyi files are supposed to help with typehints, but after the attrs pr, none of them add much to typehints.
This pr removes almost all of them, and instead adds in inline typehints, which will reduce the work needed for adding new functions and classes
The only pyi file left in is attr_utils.pyi, since it has to set up one of the functions as a dataclass field

Checklist

• I've ran pre-commit to format and lint the change(s) made.
• I've checked to make sure the change(s) work on 3.8.6 and higher.
• This fixes/solves an Issue.
  • (If existent):
• I've made this pull request for/as: (check all that apply)
  • Documentation
  • Breaking change
  • New feature/enhancement
  • Bugfix

[Catalyst4222]

The merge conflict is happening because someone changed a file that I deleted, but there's no way for me to resolve it

[EepyElvyra]

The merge conflict is happening because someone changed a file that I deleted, but there's no way for me to resolve it

Merge unstable into your branch, commit, delete the files again, commit?

[Catalyst4222]

Resolved the conflict