ENH: Update more Filters/Core to support DesiredOutputPrecision

This updates a second batch of core filters 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: I404c1bf2ea624e9065768297a1ec5247d1751647
Merge topic 'filters-core-desired-output-precision-2' into master

e5316a55 ENH: Update more Filters/Core to support DesiredOutputPrecision
ENH: Update vtkDelaunay2D to support DesiredOutputPrecision

This updates vtkDelaunay2D 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: Ib5d9149f5bb34fc4be0b5005b0e94e38fcf5b52b