By using the dual of the cellset we can quickly compute the GhostCells
of structured data using WorkletPointNeighborhood boundary condition
object

Using a 1024x1024x512 test grid we see the following perf:

Master Serial : 5.658144 sec
This MR Serial: 0.519684 sec

Master OpenMP : 0.532256 sec
This MR OpenMP: 0.080604 sec