ENH: Update vtkProcrustesAlignmentFilter to support DesiredOutputPrecision

This updates vtkProcrustesAlignmentFilter to support a choice of
desired precision (default, single, or double) for output points. It
uses the analogous code in vtkThreshold as a model.

Change-Id: Iaf82e72089b95a1787701b3d9ae7a6c4116c01a5