Backend fix login

Fixes issue #1 (closed)

Summary of changes

• UserAccount entity type added to datastore
• User's email address is checked against the database and user entity with the user's assigned roles is added to the session instead of the google account
• Created custom error AuthenticationError and moved all custom errors to a single module
• Added better exception handling and logging to the login process

api/decorators/auth.py

 from flask import session, request, Response, url_for, redirect
 from typing import List
 from functools import wraps
+from api.utils.errors import AuthenticationError
 import logging
 
 def roles_allowed(roles: List[str]):
@@ -14,10 +15,11 @@ def roles_allowed(roles: List[str]):
 
             if user and any(role in user['roles'] for role in roles):
                 # User has a required role, route request back to the original handler
+                logging.debug(f"Access granted to user: {user['email']}")
                 return func(*args, **kwargs)
-
-            logging.warning(f"Unauthorized request from: {request.remote_addr}")
-            return Response("Not authorized", 403)
+            else:
+                logging.warning(f"Unauthorized request from: {request.remote_addr}")
+                return Response("Not authorized", 403)
 
         return wrapper
     return decorator