Regression tests / Golden tests for password hashes

[Vlix]

It might be a good idea, seeing as we had a base64 major version bump, that we add golden tests to make sure the hashes we produce stay the same (for backwards compatibility). We wouldn't want a database full of passwords to suddenly not be parseable.

If anyone implements this make sure to cover the following:

• All algorithms (Argon2, bcrypt, PBKDF2, scrypt)
• Use the defaultParams per algorithm and also a custom setting that has no overlap with the defaultParams
• Double-check (only needed once) that no hashes changed compared to base64 < 1.0 (since I've just assumed it is the same, and there's no reason it wouldn't be, but I'd like verification just to be sure)
• Don't forget to add the golden files to the extra-source-files in the password.cabal

[Vlix]

Again, thank you for the effort @blackheaven