Merge branch 'Convert-import-vtk-to-import-vtkmodules.all-as-vtk' into 'master'

src/Python/GeometricObjects/Plane.py

src/Python/GeometricObjects/Planes.py

src/Python/GeometricObjects/PlanesIntersection.py

src/Python/GeometricObjects/PlatonicSolids.py

src/Python/GeometricObjects/Point.py

src/Python/GeometricObjects/PolyLine.py

src/Python/GeometricObjects/PolyLine1.py

src/Python/GeometricObjects/Polygon.py

src/Python/GeometricObjects/PolygonIntersection.py

src/Python/GeometricObjects/Polyhedron.py

src/Python/GeometricObjects/Pyramid.py

src/Python/GeometricObjects/Quad.py

src/Python/GeometricObjects/QuadraticHexahedron.py

src/Python/GeometricObjects/QuadraticHexahedronDemo.py

src/Python/GeometricObjects/QuadraticTetra.py

src/Python/GeometricObjects/QuadraticTetraDemo.py

src/Python/GeometricObjects/RegularPolygonSource.py

src/Python/GeometricObjects/ShrinkCube.py

src/Python/GeometricObjects/SourceObjectsDemo.py

src/Python/GeometricObjects/Sphere.py