Automatically add extra args to func when creating it from create signal window

Automatically add extra arguments to function when creating it from create signal window. They will be called extra_arg_1, extra_arg_2,...

editor/connections_dialog.cpp

@@ -432,6 +432,9 @@ void ConnectionsDock::_make_or_edit_connection() {
 	if (add_script_function) {
 		// pick up args here before "it" is deleted by update_tree
 		script_function_args = it->get_metadata(0).operator Dictionary()["args"];
+		for (int i = 0; i < cToMake.binds.size(); i++) {
+			script_function_args.append("extra_arg_" + itos(i));
+		}
 	}
 
 	if (connect_dialog->is_editing()) {