Only move to enabled stages
Only move to enabled stages

- Issue MatterHackers/MCCentral#5279
Staged wizard next button advances to stage which is not active

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