fix: various optimizations, idiomatic changes (#9179)

- acquire since leader lock for all background operations
  - healing, crawling and applying lifecycle policies.

- simplify lifecyle to avoid network calls, which was a
  bug in implementation - we should hold a leader and
  do everything from there, we have access to entire
  name space.

- make listing, walking not interfere by slowing itself
  down like the crawler.

- effectively use global context everywhere to ensure
  proper shutdown, in cache, lifecycle, healing

- don't read `format.json` for prometheus metrics in
  StorageInfo() call.

cmd/peer-rest-common.go

@@ -34,7 +34,6 @@ const (
 	peerRESTMethodServerUpdate                 = "/serverupdate"
 	peerRESTMethodSignalService                = "/signalservice"
 	peerRESTMethodBackgroundHealStatus         = "/backgroundhealstatus"
-	peerRESTMethodBackgroundOpsStatus          = "/backgroundopsstatus"
 	peerRESTMethodGetLocks                     = "/getlocks"
 	peerRESTMethodBucketPolicyRemove           = "/removebucketpolicy"
 	peerRESTMethodLoadUser                     = "/loaduser"