Add Chat modes to UX

[dayland]

In this PR we have added 3 separate modes under the Chat UX.

• Work Only: This limits the chat experience to only RAG based on data uploaded into Info Asst (the normal chat experience from before)
• Work + Web: This experience has a new feature that allows a user to get an answer based on data uploaded to IA, Bing search results, or compare and contrast the answers between Work and Web
• Generative (Ungounded): This experience lets the user interact with the LLM natively WITHOUT any grounded information. This IS NOT a RAG pattern.