Add an integration test for broadcast mode #1927

Job	Run time
Docker [ubuntu]	22m 9s
Build [macosx_arm64]	10m 52s
Build deps [ubuntu]	4s
Documentation	19s
Shellcheck	4s
Build [ubuntu]	8m 13s
UT [c++]	15m 35s
IT [single/legacy_mode]	3m 1s
Fuzz test [identity]	1m 27s
IT [multi/legacy_mode]	14m 44s
UT [python]	13s
Build Prometheus plugin [ubuntu]	9m 23s
Fuzz test [open_queue]	7m 52s
IT [single/fsm_mode]	3m 7s
Fuzz test [configure_queue_stream]	4m 32s
IT [multi/fsm_mode]	10m 43s
Fuzz test [put]	2m 45s
Fuzz test [confirm]	3m 35s
Fuzz test [close_queue]	17m 16s
Fuzz test [disconnect]	1m 53s
	2h 17m 47s

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