feat(BA-75): Introduce Raftify and refactor DistributedGlobalTimer with Raft#2105

jopemachine wants to merge 7 commits intomainlablup/backend.ai:mainfrom

topic/05-03-feat_introduce_raftify_and_raftglobaltimer_to_replace_distributedglobaltimerlablup/backend.ai:topic/05-03-feat_introduce_raftify_and_raftglobaltimer_to_replace_distributedglobaltimerCopy head branch name to clipboard