The `DynamicCellSet` class is now marked as deprecated (as is the header
that contains it), and all non-deprecated code is moved to its
`UnknownCellSet` replacement.
Also added a deprecation warning for the VariantArrayHandle.h header
file and deleted a couple inappropriate uses of it.
Before it was a DynamicCellSetBase<VTKM_DEFAULT_CELL_SET_LIST>. This
change causes some calls to templated DynamicCellSetBase arguments to
fail to resolve, but there were only 4 in the code base. In exchange,
DynamicCellSet requires a lot less characters in its symbol.
There was some compile errors with CUDA and the CellLocatorGeneral.
Apparently it added enough to the CUDA kernel to cause issues with
constant memory.
`CellLocatorChooser` allows you to select a cell locator at compile
time. Unlike `CellLocatorGeneral`, you have to deduce what cell set
types you might have, but you don't have to have a large switch
statement in the middle of your worklet.
