DFTTest re-implemetation (CUDA and x86)

from dfttest2 import DFTTest
output = DFTTest(input)

See also VapourSynth-DFTTest

# additional options: -D ENABLE_CUDA=ON -D ENABLE_CPU=ON
cmake -S . -B build

cmake --build build

cmake --install build

If the vapoursynth library cannot be found by pkg-config, then the cmake variable VS_INCLUDE_DIR should be set.