Allow highlighting of GraphCanvas items #22
Description
In our graph-related tools (e.g. Script Canvas, Landscape Canvas), the UI is based on a QGraphicsScene so we are unable to use the current method of searching for a specific widget/item to locate graph items (e.g. nodes). This would restrict us from writing a fully immersive tutorial that goes through Script Canvas or Landscape Canvas workflows. So, we need to extend our highlight API to give the user the ability to highlight items in the graph scene.