Bug#949569: ITP: vtkplotter-examples -- Examples set for vtkplotter

[Drew Parsons]

Upstream has reviewed the copyrights on the data files in the vtkplotter 
examples.
He's cleaned up the set up, throwing out files that weren't been used.
After review, the amount of example data files remaining is small enough 
to include in vtkplotter.

So vtkplotter-examples are folded back into vtkplotter (2020.2.3). 
vtkplotter-examples is deprecated as a standalone package.

Will close this ITP once the new vtkplotter reaches testing.

Drew