REFAC: Allow fluid rednering for all mesh types

Examples/PBD/PBDFluids/PBDFluidsExample.cpp

Examples/Rendering/RenderingExample.cpp

Source/Geometry/imstkGeometry.cpp

Source/Rendering/Materials/imstkRenderMaterial.cpp

...TKRenderer/RenderDelegate/imstkVTKFluidRenderDelegate.cpp

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

...erer/RenderDelegate/imstkVTKSurfaceMeshRenderDelegate.cpp