Create a robust testing suite

[3rdit]

We should put effort into making a clean robust pytest suite that tests many aspects of the website while this project is small.

[3rdit]

The unit testing is actually a lot better than I thought, lol

I intend to add the following:

1. Archive service testing (the upload security)
2. Comment/Solution upload (file validation/notification chain)
3. Rating system (create/update logic with recalculation)
4. ... and probably more