message: Replace `pointInRect_f` with `contains` in Window
  The new code is more clear there is a conversion to integer before
  checking for if the rect contains the point.
diff: @@ -57,7 +57,8 @@ void Window::onMouseDown(EventHandler::MouseButton button, int x, int y)
  UIContainer::onMouseDown(button, x, y);
  - mMouseDrag = (button == EventHandler::MouseButton::BUTTON_LEFT && pointInRect_f(x, y, rect().x(), rect().y(), rect().width(), sWindowTitleBarHeight));
  + const auto titleBarRect = NAS2D::Rectangle{mRect.x(), mRect.y(), mRect.width(), sWindowTitleBarHeight};
  + mMouseDrag = (button == EventHandler::MouseButton::BUTTON_LEFT && titleBarRect.to<int>().contains(NAS2D::Point{x, y}));
  }
  