feat(agent): Adds prologue functionality (#9336)

### What problem does this PR solve?

feat(agent): Adds prologue functionality #3221

- Add a prologue field to the IInputs type
- Initialize the prologue state in the chat container
- Use useEffect to monitor prologue changes and add prologue responses
### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/agent/chat/use-send-agent-message.ts

@@ -361,5 +361,6 @@ export const useSendAgentMessage = (
     resetSession,
     findReferenceByMessageId,
     appendUploadResponseList,
+    addNewestOneAnswer,
   };
 };