Re-query speaker name when multiple speaker names returned during Group Chat speaker selection (#2304)

* Added requery_on_multiple_speaker_names to GroupChat and updated _finalize_speaker to requery on multiple speaker names (if enabled)

* Removed unnecessary comments

* Update to current main

* Tweak error message.

* Comment clarity

* Expanded description of Group Chat requery_on_multiple_speaker_names

* Reworked to two-way nested chat for speaker selection with default of 2 retries.

* Adding validation of new GroupChat attributes

* Updates as per @ekzhu's suggestions

* Update groupchat

- Added select_speaker_auto_multiple_template and select_speaker_auto_none_template
- Added max_attempts comment
- Re-instated support for role_for_select_speaker_messages
-

* Update conversable_agent.py

Added ability to force override role for a message to support select speaker prompt.

* Update test_groupchat.py

Updated existing select_speaker test functions as underlying approach has changed, added necessary tests for new functionality.

* Removed block for manual selection in select_speaker function.

* Catered for no-selection during manual selection mode

---------

Co-authored-by: Chi Wang <wang.chi@microsoft.com>

Author: marklysze

autogen/agentchat/conversable_agent.py

@@ -576,6 +576,11 @@ def _append_oai_message(self, message: Union[Dict, str], role, conversation_id:
 
         if message.get("role") in ["function", "tool"]:
             oai_message["role"] = message.get("role")
+        elif "override_role" in message:
+            # If we have a direction to override the role then set the
+            # role accordingly. Used to customise the role for the
+            # select speaker prompt.
+            oai_message["role"] = message.get("override_role")
         else:
             oai_message["role"] = role