fix: handle concurrent lockers with multiple optimizations (#10640)

- select lockers which are non-local and online to have
  affinity towards remote servers for lock contention

- optimize lock retry interval to avoid sending too many
  messages during lock contention, reduces average CPU
  usage as well

- if bucket is not set, when deleteObject fails make sure
  setPutObjHeaders() honors lifecycle only if bucket name
  is set.

- fix top locks to list out always the oldest lockers always,
  avoid getting bogged down into map's unordered nature.

cmd/erasure-sets.go

@@ -273,6 +273,13 @@ func (s *erasureSets) GetLockers(setIndex int) func() ([]dsync.NetLocker, string
 	return func() ([]dsync.NetLocker, string) {
 		lockers := make([]dsync.NetLocker, s.setDriveCount)
 		copy(lockers, s.erasureLockers[setIndex])
+		sort.Slice(lockers, func(i, j int) bool {
+			// re-order lockers with affinity for
+			// - non-local lockers
+			// - online lockers
+			// are used first
+			return !lockers[i].IsLocal() && lockers[i].IsOnline()
+		})
 		return lockers, s.erasureLockOwner
 	}
 }