Fixed http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-782

This submission fixes the geometry display for all the statements in
CBN. It also allows geometry to be viewed in Watch3D node. At this
moment Watch3D node displays all the geometry created by the node, it
doesn't distinguish the geometry coming from specific output port.

GetAllDrawablesInModel() queries the variable name corresponding to each output port in the codeblock node and then for those variables it queries the graphic items and updates the render description with the visualization manager.