Rehash user password on authentication with password

[kimitrii]

Changes Made

This PR implements password rehashing during user authentication. When a user successfully authenticates using their email/username and password, the system will rehash their password using the latest bcrypt settings and save the updated hash in the database. This enhancement ensures that passwords are continually secured with the most up-to-date hashing standards and higher salt, providing additional protection against potential brute-force attacks as computational capabilities evolve.

Resolves #45

Changes Type

• New feature

Checklist:

• The changes do not generate new error logs or warnings.
• I have added tests that prove the fix or new feature works as expected.
• Both new and existing tests pass locally.