I-ViT Integration

Context

Add the support for I-ViT operators ILayerNorm, ShiftGELU and ShiftMax

Modified files

• ILayerNorm.hpp and ILayerNorm.cpp, add ILayerNorm operator;
• ShiftMax.hpp and ShiftMax.cpp, add ShiftMax operator;
• ShiftGELU.hpp and ShiftGELU.cpp, add ShiftGELU operator;
• aidge.hpp to include the operator;