Create vtkPolyData instead of vtkUnstructuredGrid when passing points.

This is a feature / performance request.

Change-Id: I3f8745a4591f19a8ce0960ae82af328816b4e6fa
Merge topic '0014369-vtkExtractSelectedIds-Output-vtkPolyData' into master

c1d37686 Create vtkPolyData instead of vtkUnstructuredGrid when passing points.