Significant updates to agbench. #4411

Job	Run time
mypy (./packages/autogen-core)	3m 38s
mypy (./packages/agbench)	1m 7s
mypy (./packages/autogen-ext)	3m 13s
check-proto-changes-python	1m 23s
mypy (./packages/autogen-agentchat)	1m 34s
docs (./packages/autogen-core)	1m 47s
docs-example-check (./packages/autogen-core)	3m 10s
mypy (./packages/magentic-one-cli)	1m 24s
format	49s
lint	55s
markdown-code-lint	2m 21s
pyright (./packages/autogen-core)	56s
samples-code-check	1m 10s
pyright (./packages/agbench)	54s
pyright (./packages/autogen-ext)	1m 9s
test (./packages/autogen-core)	1m 2s
pyright (./packages/autogen-agentchat)	1m 0s
test (./packages/autogen-ext)	4m 28s
pyright (./packages/magentic-one-cli)	56s
test (./packages/autogen-agentchat)	1m 17s
codecov (./packages/autogen-core)	12s
codecov (./packages/autogen-ext)	9s
codecov (./packages/autogen-agentchat)	9s
	34m 43s

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