Add envmap to the visualization renderer.

src/DemoApp/main.cpp

src/libRender/RadiumNBR/Gui/VisualizationGui.cpp

src/libRender/RadiumNBR/Passes/CustomAttribToColorPass.cpp

src/libRender/RadiumNBR/Passes/CustomAttribToColorPass.hpp

src/libRender/RadiumNBR/Renderer/FullFeatureRenderer.hpp

src/libRender/RadiumNBR/Renderer/Visualization.cpp

src/libRender/RadiumNBR/Renderer/Visualization.hpp