Implement new auth system

[hrideshmg]

Currently the backend uses the django rest framework's TokenAuthentication system for serving and managing user tokens. There are several drawbacks to this systems including but not limited to -

1. Tokens being limited to one per user which means that users cannot sign into the website and mobile app at the same time.
2. Tokens are stored without encryption in the database
3. Tokens don't have any expiry time

There are a few potential systems that we could use instead:
https://github.com/jazzband/django-rest-knox
https://github.com/jazzband/django-oauth-toolkit?tab=readme-ov-file
https://github.com/pennersr/django-allauth

[hrideshmg]

Decided to use django-rest-knox since allauth requires additional configuration for compatibility with DRF