Allow image based questions from `/api/conversation/azure_byod`

[adamdougal]

Required by https://github.com/Azure-Samples/chat-with-your-data-solution-accelerator/issues/323

Description

When calling the /api/conversation/azure_byod endpoint, generate embeddings of the question using computer vision and query the image embeddings using the question embeddings. We should continue to create question embeddings using text-embeddings-ada-002 in addition to be used to search the image description.

Tasks

• [ ] Generate question embeddings using computer vision
• [ ] Query the search index using the generated embeddings
• [ ] Pass any returned images to gpt-4-vision along with the chat