message: Update onMove event handler to take packed Vector parameter
diff: @@ -17,7 +17,7 @@ class Control
  {
  public:
  using ResizeCallback = NAS2D::Signal<Control*>;
  - using PositionChangedCallback = NAS2D::Signal<int, int>;
  + using PositionChangedCallback = NAS2D::Signal<NAS2D::Vector<int>>;
  Control() = default;
  virtual ~Control() = default;
  @@ -65,7 +65,7 @@ protected:
  * \param dX Difference in X Position.
  * \param dY Difference in Y Position.
  */
  - virtual void positionChanged(int dX, int dY) { mPositionChanged(dX, dY); }
  + virtual void positionChanged(int dX, int dY) { mPositionChanged({dX, dY}); }
  void positionChanged(NAS2D::Vector<int> displacement) { positionChanged(displacement.x, displacement.y); }
  virtual void visibilityChanged(bool /*visible*/) {}
  