Add IBC from VTM3.0 to master

source/Lib/CommonLib/CodingStructure.cpp

source/Lib/CommonLib/ContextModelling.cpp

source/Lib/CommonLib/ContextModelling.h

source/Lib/CommonLib/Contexts.cpp

source/Lib/CommonLib/Contexts.h

source/Lib/CommonLib/InterPrediction.cpp

source/Lib/CommonLib/MotionInfo.h

source/Lib/CommonLib/Slice.cpp

source/Lib/CommonLib/Slice.h

source/Lib/CommonLib/TypeDef.h

source/Lib/CommonLib/Unit.cpp

source/Lib/CommonLib/Unit.h

source/Lib/CommonLib/UnitTools.cpp

source/Lib/CommonLib/UnitTools.h

source/Lib/DecoderLib/CABACReader.cpp

source/Lib/DecoderLib/DecCu.cpp

source/Lib/DecoderLib/DecLib.cpp

source/Lib/DecoderLib/VLCReader.cpp

source/Lib/EncoderLib/CABACWriter.cpp

source/Lib/EncoderLib/EncCu.cpp