The enumerations in `vtkm::cont::Field::Association` were renamed in the
previous commit. The old names still exist, but are deprecated. Change
the rest of the code to use the new names.
There were several places in the code that had to check the type of an
`UnknownArrayHandle` and conditionally get or copy that array. This code
is simplified by using `ArrayCopyShallowIfPossible`.
`VaraintArrayHandle` has been replaced by `UnknownArrayHandle` and
`UncertainArrayHandle`. Officially make it deprecated and point users to
the new implementations.
The circular dependency came from UnknownArrayHandle.h needing
VTKmDefaultTypes.h, which needed all the cell set types. Some of those
cell sets used ArrayCopy in templated functions. Changed those functions
to directly deep copy the ArrayHandle.
