Integrate AgentOptimizer (#1767)

* draft agent optimizer

* refactor

* remove

* change openai config interface

* notebook

* update blog

* add test

* clean up

* redir

* update

* update interface

* change model name

* move to contrib

* Update autogen/agentchat/contrib/agent_optimizer.py

Co-authored-by: Jack Gerrits <jackgerrits@users.noreply.github.com>

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Co-authored-by: “skzhang1” <“shaokunzhang529@gmail.com”>
Co-authored-by: Beibin Li <BeibinLi@users.noreply.github.com>
Co-authored-by: Jieyu Zhang <jieyuz2@cs.washington.edu>
Co-authored-by: Jack Gerrits <jackgerrits@users.noreply.github.com>