NVCODEC + Y444
Tested on Gstreamer 1.19.3
Since Turing architecture, Nvidia cards can decode YUV 444 (H264 + H265) https://developer.nvidia.com/video-encode-and-decode-gpu-support-matrix-new
gstnvdech264dec.c and gstnvdech265dec.c only support chroma_format_idc = 1 (YUV 420) : new case needed for chroma_format_idc = 3 (YUV 444)
gsth265parser.c need evolutions for 444 chroma constraints.