Update the interface and documentation of GhostCellRemove

The GhostCellRemove filter had some methods inconsistent with the naming convention elsewhere in VTK-m. The class itself was also in need of some updated documentation. Both of these issues have been fixed.

Additionally, there were some conditions that could lead to unexpected behavior. For example, if the filter was asked to remove only ghost cells and a cell was both a ghost cell and blank, it would not be removed. This has been updated to be more consistent with expectations.