feature: delete all pinecone data api

bugfix: fixed create one train_document issue

bugfix: fixed update train

feature(#9): pinecone key management

feature(#9): firebase key management

feature(#35): fix json parsing issue in train_all_documents function.

feature(#35): fix some issues.

feature(#35): change get_pinecone_index_train_namespace function path.

feature(#35): implement train logic.