Add current handler to filters, so that flags can be retrieved from it.

aiogram/dispatcher/event/telegram.py

@@ -109,9 +109,10 @@ class TelegramEventObserver:
         Handler will be called when all its filters are pass.
         """
         for handler in self.handlers:
+            kwargs['handler'] = handler
             result, data = await handler.check(event, **kwargs)
             if result:
-                kwargs.update(data, handler=handler)
+                kwargs.update(data)
                 try:
                     wrapped_inner = self.outer_middleware.wrap_middlewares(
                         self._resolve_middlewares(),