ENH: Color functions for surface and point meshes render delegates

...les/TaskGraph/Configuration/taskGraphConfigureExample.cpp

Source/Common/imstkColorFunction.h

Source/Geometry/Mesh/imstkPointSet.h

Source/Rendering/Materials/imstkRenderMaterial.h

...enderer/RenderDelegate/imstkVTKPointSetRenderDelegate.cpp

...KRenderer/RenderDelegate/imstkVTKPointSetRenderDelegate.h

...ing/VTKRenderer/RenderDelegate/imstkVTKRenderDelegate.cpp

...erer/RenderDelegate/imstkVTKSurfaceMeshRenderDelegate.cpp

...nderer/RenderDelegate/imstkVTKSurfaceMeshRenderDelegate.h