Use dall-e-3 and better prompt to create character consistency for gr… #1

Job	Run time
check-proto-changes-python	18s
docs (./packages/autogen-core)	43s
format	19s
lint	27s
mypy (./packages/autogen-core)	1m 30s
pyright (./packages/autogen-core)	35s
mypy (./packages/autogen-magentic-one)	38s
pyright (./packages/autogen-magentic-one)	26s
mypy (./packages/agbench)	24s
test (./packages/autogen-core)	42s
pyright (./packages/agbench)	30s
test (./packages/autogen-magentic-one)	58s
pyright (./packages/autogen-ext)	31s
mypy (./packages/autogen-ext)	54s
test (./packages/autogen-ext)	1m 19s
mypy (./packages/autogen-agentchat)	37s
pyright (./packages/autogen-agentchat)	23s
test (./packages/autogen-agentchat)	25s
	11m 39s

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