JVET-O0047/O0058/O0064/O0067/O0290/O0301/O0430: simplificed ALF clipping parameter coding
requested to merge nanh/VVCSoftware_VTM:JVET-O0047/O0058/O0064/O0067/O0290/O0301/O0430-Simp-Alf-clip-coding into master
JVET-O0047/O0058/O0064/O0067/O0290/O0301/O0430: use fixed-length codes (2 bits) for alf clipping indices, always signal alf clipping indices