Add optimization loop performance metrics#981

jia-gao wants to merge 2 commits intollm-d:mainllm-d/llm-d-workload-variant-autoscaler:mainfrom

jia-gao:feat/optimization-loop-metrics-914jia-gao/llm-d-workload-variant-autoscaler:feat/optimization-loop-metrics-914Copy head branch name to clipboard