promote empty chunk tolerance param into ChatCompletionClient #3910

Job	Run time
format	56s
docs (./packages/autogen-core)	1m 57s
lint	1m 1s
mypy (./packages/autogen-core)	3m 22s
mypy (./packages/autogen-magentic-one)	1m 22s
mypy (./packages/agbench)	1m 4s
pyright (./packages/autogen-core)	5m 43s
mypy (./packages/autogen-ext)	2m 55s
pyright (./packages/autogen-magentic-one)	1m 22s
test (./packages/autogen-core)	1m 37s
pyright (./packages/agbench)	1m 13s
mypy (./packages/autogen-agentchat)	1m 26s
test (./packages/autogen-magentic-one)	1m 57s
mypy (./packages/magentic-one-cli)	1m 28s
test (./packages/autogen-ext)	4m 16s
pyright (./packages/autogen-ext)	1m 6s
test (./packages/autogen-agentchat)	1m 6s
pyright (./packages/autogen-agentchat)	1m 16s
pyright (./packages/magentic-one-cli)	1m 1s
check-proto-changes-python	1m 13s
docs-example-check (./packages/autogen-core)	3m 5s
markdown-code-lint	2m 8s
samples-code-check	1m 4s
codecov (./packages/autogen-core)	9s
codecov (./packages/autogen-magentic-one)	13s
codecov (./packages/autogen-ext)	13s
codecov (./packages/autogen-agentchat)	14s
	44m 27s

Provide feedback