ENH: updating level sets sparse layer visualization

Make the corresponding class inherit from itk::VTKVisualizeImageLevelSet and
rename vtkVisualize* classes itk::VTKVisualize* to make it consistent with
other visualization classes.

Change-Id: Ie222cfa341c3c35c5e04d7f39db50e3a0d3ef7f5
Merge topic 'LayersVisu'

d359d19 ENH: updating level sets sparse layer visualization