Support RAG controller

[bangqipropel]

KAITO RagEngine updates:

• Retrieval augmented generation (RAG) in KAITO leverages Llamaindex for orchestration and supports Faiss as the default vectorDB.
• RagEngine can interface directly with a KAITO workspace by calling its endpoints and is composed of two steps:
  1. Indexing: user provides data to index via HTTP request, then KAITO takes care of indexing that data into Faiss.
  2. Querying: user hits the "query" endpoint that gathers the relative context and then conducts inference.
• Check out the API here

[rudrakshkarpe]

Hi @bangqipropel, could you please add description about this issue? I'd like to know your current approach to provide RAG controller support and contribute to it, looking forward to hearing from you :)