Update conversation ID in copilot studio client when start_conversation is called (#195)

* Update conversation ID in copilot studio client when start_conversation is called from response header

* Update copilot_client.py

Removed trailing space to fix formatting

* Fixed black formatting

---------

Co-authored-by: Dinesh Kumar Devamanoharan <[email protected]>

Author: dineshkumar31

libraries/microsoft-agents-copilotstudio-client/microsoft_agents/copilotstudio/client/copilot_client.py

@@ -35,6 +35,12 @@ async def post_request(
                     raise aiohttp.ClientError(
                         f"Error sending request: {response.status}"
                     )
+
+                # Set conversation ID from response header when status is 200
+                conversation_id_header = response.headers.get("x-ms-conversationid")
+                if conversation_id_header:
+                    self._current_conversation_id = conversation_id_header
+
                 event_type = None
                 async for line in response.content:
                     if line.startswith(b"event:"):