Reworked composite embeddings

modules/generative_head/composite_head_A.py

modules/generative_head/composite_head_B.py

modules/generative_head/composite_head_C.py

modules/generative_head/composite_head_D.py

modules/generative_head/convolution_head.py

modules/generative_head/double_substitution_head.py

modules/generative_head/head_factory.py

modules/generative_head/substitution_head.py

modules/token_embedding/basic_embedding.py

modules/token_embedding/composite_embedding_A.py

modules/token_embedding/composite_embedding_B.py

modules/token_embedding/composite_embedding_C.py

modules/token_embedding/composite_embedding_D.py

modules/token_embedding/convolution_embedding.py

modules/token_embedding/embedding_factory.py

modules/utils/block_convolution.py

utils/loss/loss_factory.py