Add the Fixstars/libSGM algorithm

cv-node/CMakeLists.txt

cv-node/cmake/FindLibSGM.cmake

cv-node/config/config.json

cv-node/include/ftl/algorithms/fixstars_sgm.hpp

cv-node/include/ftl/algorithms/opencv_bm.hpp

cv-node/src/algorithms/fixstars_sgm.cpp

cv-node/src/algorithms/opencv_bm.cpp

cv-node/src/algorithms/opencv_sgbm.cpp

cv-node/src/main.cpp