add type annotations to every funtion

[michelkluger]

the reason to do this is to have more clarity for future development,

• [ ] every input param should be annotated
• [ ] every output as well

acceptance criteria:

• [x] mypy should pass using python 3.12
• [ ] add mypy to CI

[michelkluger]

study mypy and understand what is mypy understand typing annotation in python

https://www.youtube.com/watch?v=bO3-CWDMxCk https://www.youtube.com/watch?v=QORvB-_mbZ0&t=560s