Draft: Move app kinect_viewer_cuda to general app directory

[SunBlack]

Following-up of #5528

Currently only draft, as there some issues:

• topological_sort sorts apps before cuda => didn't debugged why, but called add_subdirectory separately to solve this issue
• See,s the CUDA target have wrong include directories defined as it is including now pcl/cuda/include instead of ``pcl/cuda/io/include` (therefore Draft as I didn't found a fast workaround for it)

[larshg]

collect_subproject_directory_names only search first level of directories, ie. it finds cuda and gpu... But not subdirectories. So its flawed. I tried to use a GPU method in benchmarks and I just experienced the same. Didn't find a good solution either.