[Feat](sleep mode): implement sleep and wake_up APIs for engine lifecycle management#1160

Flink-ddd wants to merge 2 commits into

vllm-project:mainvllm-project/vllm-omni:mainfrom

Flink-ddd:fix/omni-sleep-fp8-garbageFlink-ddd/vllm-omni:fix/omni-sleep-fp8-garbageCopy head branch name to clipboard