fix: Overall type-hinting improvements

[yoggys]

Summary

Overall code type-hinting improvements.

Information

• [x] This PR fixes an issue.
• [ ] This PR adds something new (e.g. new method or parameters).
• [ ] This PR is a breaking change (e.g. methods or parameters removed/renamed).
• [x] This PR is not a code change (e.g. documentation, README, typehinting, examples, ...).

Checklist

• [x] I have searched the open pull requests for duplicates.
• [ ] If code changes were made then they have been tested.
  • [ ] I have updated the documentation to reflect the changes.
• [x] If type: ignore comments were used, a comment is also left explaining why.
• [x] I have updated the changelog to include these changes.

[yoggys]

I think I caught most of what was wrong, this PR overwrites #2456 at the same time because I transferred the changes to this branch (so if it's ok then that one can be closed).

[yoggys]

@plun1331 by now it should be all there, you can look at it at your free time