Typing: Narrow down types of arguments (NDFrame)
- [x] closes parts of # 10 (in https://github.com/noatamir/pydata-workshop)
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.

Updated item 11-14 (15 seemed already done):
 - [x] Specify method in to_sql more precisely
 - [x] Specify errors in to_csv more precisely
 - [x] Specify mode in to_csv more precisely
 - [x] Specify kind and na_position in sort_values more precisely
@phofl @noatamir  Thanks for the PR @kjanker! There are a couple of errors identified by pre-commit, which I think you can solve yourself. Let me know if you need help understanding the errors. Thanks @kjanker!