JVET-R0098: Only signall LMCS and explicit scaling list enable flags in SH when PH is not in SH
requested to merge jonatan/VVCSoftware_VTM:JVET_R0098_LMCS_AND_SCALING_LISTS_FOR_PH_IN_SH into master
JVET-R0098: When picture header is signalled in slice header, the flags for LMCS and explicit scaling lists are not signalled, and instead derived from the values in the picture header.