Introduce vtkForceStaticMesh filter

The notion of static mesh refers to temporal dataset having varying attributes on a static geometry. In VTK data model terms, this is supported by both the vtkPolyData and vtkUnstructuredGrid, through their GetMeshMTime().

This filter takes any vtkDataSet of vtkCompositeDataSet as input and caches its geometry. Subsequent requests will only lead to attributes update, thus leading to a valid static mesh output (as long as the number of points / cells stay the same).

It is up to following filters to use the GetMeshMTime() method for performance improvements.