Implements #141 normals

Calculate and visualise smoothed normals. The smoothing could be improved to dynamically adjust the smoothing level.

components/renderers/cpp/include/ftl/cuda/normals.hpp

@@ -6,7 +6,7 @@
 namespace ftl {
 namespace cuda {
 
-void ftl::cuda::normals(ftl::cuda::TextureObject<float4> &output,
+void normals(ftl::cuda::TextureObject<float4> &output,
         ftl::cuda::TextureObject<float4> &input, cudaStream_t stream);
 
 }