refactor(chatto): delegate _is_allowed_user_id to _is_authorized

adapter.py

@@ -1777,14 +1777,7 @@ class ChattoAdapter(BasePlatformAdapter):
         including a login looked up from ``_user_cache`` when the id itself
         is not listed. Fail-closed when neither setting allows anyone.
         """
-        if self.chatto_config.allow_all_users.value:
-            return True
-        allowed = self.chatto_config.allowed_users.value
-        if user_id in allowed:
-            return True
-        user = self._user_cache.get(user_id)
-        login = user.login if user is not None else None
-        return login is not None and login in allowed
+        return self._is_authorized(user_id)
 
     def _evict_roster(self, room_id: str) -> None:
         """Drop all roster state for a room.