As an EmbeddedChat developer

I need to:
I need to implement a feature that fetches and loads older messages when a user scrolls to the top of the chat screen

So That:
users can seamlessly view the chat history without refreshing the page or manually triggering a request.

Acceptance Criteria

• When the user scrolls to the top of the chat screen, a request should be sent to the backend to fetch older messages using the appropriate parameters.
• The older messages fetched from the backend should be appended to the top of the existing message list in the chat view without losing the current scroll position.
• Ensure that the Throbber indicator is displayed while the older messages are being fetched.