RAG ingestion and chat pipelines

[dmartinol]

Introducing ilab commands changes to support the RAG ingestion and chat pipelines:

• RAG conversion: a new command to process customer documentation. Either from knowledge taxonomy or from actual user documents.
• RAG ingestion: a new command to generate and ingest embeddings from pre-processed documents into a configured vector store.
• RAG chat: augment the context of the chat command with the result of a similarity search executed on the ingested database, to increase the accuracy of the response.