Set padding after computing leftRightMargin
Set padding after computing leftRightMargin

- Issue MatterHackers/MCCentral#2151
Investigate LibraryQueueViewRefreshesOnAddItem failure

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