Add non-public {Line,Text}Edit::_set_text()

- [Web] Fix "Enter" not triggering LineEdit submits.

Co-authored-by: Marwen Azouzi <marwen.azouzi@datadoghq.com>

platform/web/display_server_web.cpp

@@ -796,7 +796,7 @@ void DisplayServerWeb::_vk_input_text_callback(const String &p_text, int p_curso
 		return;
 	}
 	// Call input_text
-	ds->input_text_callback.call(p_text);
+	ds->input_text_callback.call(p_text, true);
 	// Insert key right to reach position.
 	Input *input = Input::get_singleton();
 	Ref<InputEventKey> k;