message: Use UIContainer to propagate calls to `update()`
diff: @@ -192,9 +192,7 @@ void ComboBox::setSelected(std::size_t index) {
  void ComboBox::update()
  {
  - txtField.update();
  - btnDown.update();
  - lstItems.update();
  + mContainer.update();
  }
  void ComboBox::text(const std::string& text) {
  