Set up users and auth with JWT

[CHATALOT1]

• SeaORM and serde compatible implementation of User (described below) to be used with listed endpoints
• Endpoints
  • Create user
  • Login (serves JWT with expiry)
  • Delete user
  • Invalidate Session/Logout/Invalidate all sessions
  • Change password
  • Include password hashing with (probably) bcrypt
  • Use SeaORM and postgres
• Client implementation for all endpoints above
• Extractor for processing JWT

User includes:

• Unique username
• ID
• Hashed password
• Last login timestamp
• Display name
• User created timestamp
• Last invalidate all sessions timestamp

Auth JWT claims include

• iat (Issued at)
• exp (Expiration time)
• sub (contains User ID of the user)