The OptionsUI and UndoUI are no longer drawn in the BarrelNode, DoorNode,
WindowNode, ClinicNode, and HouseNode. These nodes draw sprites that can
conflict with the UIs, because they are all in the same layer. By creating
a SceneNode class to draw each UI the layer that the UI is attached to can
be controlled. The BarrelUINode, DoorUINode, WindowUINode, ClinicUINode,
and HouseUINode are attached to the foreground. While the BarrelNode,
DoorNode, WindowNode, ClinicNode, and HouseNode are attached to the
Interactive layer.