Fixes for colourising and blending

applications/gui/src/camera.cpp

components/renderers/cpp/include/ftl/render/CUDARender.hpp

components/renderers/cpp/include/ftl/render/renderer.hpp

components/renderers/cpp/src/CUDARender.cpp

components/renderers/cpp/src/colour_cuda.hpp

components/renderers/cpp/src/colour_util.cu

components/renderers/cpp/src/colouriser.cpp

components/renderers/cpp/src/normals.cu