Merge branch 'ywchen/VVCSoftware_VTM-N0324-RegularMrgFlag'

source/Lib/CommonLib/ContextModelling.cpp

source/Lib/CommonLib/Contexts.cpp

source/Lib/CommonLib/Contexts.h

source/Lib/CommonLib/TypeDef.h

source/Lib/CommonLib/Unit.cpp

source/Lib/CommonLib/Unit.h

source/Lib/DecoderLib/CABACReader.cpp

source/Lib/EncoderLib/CABACWriter.cpp

source/Lib/EncoderLib/EncCu.cpp

source/Lib/EncoderLib/InterSearch.cpp