Port y4m support from VTM
Port y4m support from VTM (jvet/VVCSoftware_VTM!2246 (merged)). It supports reading from y4m files and decoding to y4m files based on file extension. It has no impact on bitstreams.
Port y4m support from VTM (jvet/VVCSoftware_VTM!2246 (merged)). It supports reading from y4m files and decoding to y4m files based on file extension. It has no impact on bitstreams.