Json config list, agent refactoring and new notebooks (#1133)

* simplify the initiation of chat

* version update

* include openai

* completion

* load config list from json

* initiate_chat

* oai config list

* oai config list

* config list

* config_list

* raise_error

* retry_time

* raise condition

* oai config list

* catch file not found

* catch openml error

* handle openml error

* handle openml error

* handle openml error

* handle openml error

* handle openml error

* handle openml error

* close #1139

* use property

* termination msg

* AIUserProxyAgent

* smaller dev container

* update notebooks

* match

* document code execution and AIUserProxyAgent

* gpt 3.5 config list

* rate limit

* variable visibility

* remove unnecessary import

* quote

* notebook comments

* remove mathchat from init import

* two users

* import location

* expose config

* return str not tuple

* rate limit

* ipython user proxy

* message

* None result

* rate limit

* rate limit

* rate limit

* rate limit