No way to send custom error from on_connect when using GraphQLTransportWSHandler

[vlaci]

When using the 'legacy' handler, I can send custom errors from on_connect as documented, because of the special Handling of WebSocketConnectionError at

ariadne/ariadne/asgi/handlers/graphql_ws.py

Lines 250 to 251 in a9cca4f

	if isinstance(error, WebSocketConnectionError):
	payload = error.payload # pylint: disable=no-member

The same special handling is missing from GraphQLTransportWSHandler

ariadne/ariadne/asgi/handlers/graphql_transport_ws.py

Lines 226 to 228 in a9cca4f

	except Exception as error:
	log_error(error, self.logger)
	await websocket.close()

It would be nice if at least the error code could be overridden to signal authorization errors to the client.