Draft: Support general tuple sizes when converting arrays from VTK-m to VTK

Previously, the conversion from a vtkm::cont::UnknownArrayHandle to a vtkDataArray relied on the array being a known Vec size. This restriction has been lifted, and tuples of any size can be converted from an ArrayHandleBasic or an ArrayHandleSOA to an vtkAOSDataArrayTemplate or vtkSOADataArrayTemplate, respectively.

The code is also more clever about when to copy data to VTK. It avoids transferring the data if it means copying data from device to host.