Perform colour conversion on encode

components/codecs/include/ftl/codecs/bitrates.hpp

components/codecs/include/ftl/codecs/encoder.hpp

components/codecs/include/ftl/codecs/nvpipe_encoder.hpp

components/codecs/include/ftl/codecs/opencv_encoder.hpp

components/codecs/src/encoder.cpp

components/codecs/src/nvpipe_decoder.cpp

components/codecs/src/nvpipe_encoder.cpp

components/codecs/src/opencv_encoder.cpp

components/rgbd-sources/include/ftl/rgbd/streamer.hpp

components/rgbd-sources/src/streamer.cpp