Annotate Python type hints

[zebrapurring]

This PR adds type hints to the Python functions, which help making the code more readable and maintainable. Development bugs such as #1023 can also be easily spotted in a properly typed codebase.

I didn't add typings for all the functions in the project, but I tried to cover the most used ones.

[ehrenb]

Hi, I am working on a more comprehensive pass at applying types to the entire project here: https://github.com/ehrenb/androguard/tree/typing. I think the related issue got closed here, which makes it less obvious that this was ongoing (#989 (comment)).

Also, the upgrade for PyQT5-QT5 will break the install for anyone not running MacOS I believe, see: #1018.

[erev0s]

Hi @zebrapurring, I want to emphasize that your contribution is valued, but was decided to go with another PR from @ehrenb (#1042) because it covers more ground and provides a more comprehensive solution. Thank you for your understanding and effort.

[zebrapurring]

Hi @erev0s, no problem I just started this PR to add some basic coverage but didn't have time to follow up. Glad to see some typing support in mainline.