Refactor event retrieval and improve test coverage

Removed redundant code for event retrieval and standardized logic by introducing a unified method for generating event endpoints. Updated tests to align with these changes, adding support for slug-based access and handling finer permission cases. Minor issues with test formatting and comments were also addressed.

backend/app/api/routes/events/router.py

@@ -239,7 +239,6 @@ def get_event(
         current_user: Optional[User] = Depends(get_current_user)
 ) -> EventResponse:
     """Get event by ID."""
-    print("Getting event")
     try:
         event_obj = event.get(db=db, id=event_id)
         return validate_event_access(
@@ -270,8 +269,7 @@ def get_event_by_slug(
 ) -> EventResponse:
     """Get event by slug."""
     try:
-        event_obj = event.get_public_event(db=db, slug=slug, access_code=access_code)
-
+        event_obj = event.get_by_slug(db=db, slug=slug)
         return validate_event_access(
             db=db,
             event_obj=event_obj,