Ensure points in extracted selection match type of input points

New points in the extracted selection were always stored in single
precision (the default buffer type for vtkPoints). Fixed that by
setting the point precision type to the same as the input point set
precision type for vtkPointSets. Datasets with implicit points (e.g.,
vtkImageData) will have vtkPoints with single precision. Modified
existing test to ensure that the point precision is carried through
the extraction.
15 jobs for extract-selection-point-precision
Status Job ID Name Coverage
  External
passed cdash

passed ghostflow-branch-check-master

failed vtk@master-adora-linux-shared-release+gcc+mpi+python2+qt+tbb+vtkm

failed vtk@master-bigmac-osx-shared-debug+clang+python2+vtkm

00:07:12

failed vtk@master-dejagore-linux-shared-release+gcc+mpi+openmp+python2+qt+vtkm

00:11:29

failed vtk@master-duma-linux-shared-release+osmesa+ospray

00:00:21

failed vtk@master-eeloo-linux-shared-release+extdeps+java+mpi+python3+qt+tbb+vtkm

00:04:11

passed vtk@master-eeloo-linux-shared-release+mpi+nogl

00:00:50

failed vtk@master-luigi-linux-shared-release+mpi+python2+tbb

00:06:01

failed vtk@master-mun-windows-shared-release+kits+mpi+python3+qt+tbb

00:04:54

failed vtk@master-mun-windows-shared-release+mpi+python3+tbb+vtkm

00:06:35

failed vtk@master-mun-windows-static-release+mpi+qt+tbb

00:04:39

failed vtk@master-taanab-linux-shared-release+mpi+python2

00:03:21

failed vtk@master-trey-osx-shared-release+python3+qt

00:09:41

failed vtk@master-adora-linux-shared-release+gcc+mpi+python2+qt+tbb+vtkm

00:54:43