[Issue]: order agents within a groupchat for round_robin to work

[filippopirri]

Describe the issue

At the moment, agents added to a groupchat container are retrieved ordered by created date (descending). This clearly causes an issue with round_robin. The fix will be to keep track of the ordering (as agents are added to a groupchat container) and use that detail in ordering the agents before they are created.

Steps to reproduce

1. Create user_proxy agent
2. Create assistant agent
3. Create groupchat, and add assistant agent first, user_proxy second
4. The user_proxy agent will always be consider first in the groupchat because of current ordering logic: agent desc created date
5. Test the groupchat with selection_method: round_robin. user_proxy will run first, and chat terminates immediately

Screenshots and logs

Additional Information

No response

[Hk669]

@filippopirri we'd greatly appreciate it if you could create a pull request. thanks

cc @victordibia