Wire up sort menu to active state
Wire up sort menu to active state

- Issue MatterHackers/MCCentral#2865
Add sorting fields to ILibraryItem as promised by sort menu

jlewin/MatterControl,mmoening/MatterControl,larsbrubaker/MatterControl,larsbrubaker/MatterControl,larsbrubaker/MatterControl,larsbrubaker/MatterControl,unlimitedbacon/MatterControl,unlimitedbacon/MatterControl,jlewin/MatterControl,jlewin/MatterControl,unlimitedbacon/MatterControl,mmoening/MatterControl,unlimitedbacon/MatterControl,mmoening/MatterControl,jlewin/MatterControl