add google auth, remove JWT and bcrypt

[lmaotrigine]

This addresses issues #3, #5, and #6.

Summary

• Remove bcrypt and JWT flask extensions.
• Add a minimal PASETO implementation by yours truly that only serves this purpose
• Implement Google OAuth endpoints
• Update requirements.txt to work on more platforms and only contain needed libraries. This is currently managed by poetry, which I didn't want to include in this project until further discussion.
• Update documentation to include minimum python version, database setup instructions, new environment variables, and Google OAuth application set up. Also added a note on virtual environments.

Once this is merged, sinsniwal/iitm-server-bot#17 can be implemented by creating new endpoints here.