[Trainer] Corrects typing of Trainer __init__ args 
# What does this PR do?

Corrects typing for Trainer class. Updates typing to match change made in https://github.com/huggingface/transformers/pull/19158/ and fixes a few other typing issues while I'm there

Unless I'm missing something these changes take the typing to parity with both class docstring and implementation 

Who can review: @sgugger

## Before submitting
- [X] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).

_The documentation is not available anymore as the PR was closed or merged._