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/local-locker.go

@@ -203,11 +203,16 @@ func (l *localLocker) Close() error {
 	return nil
 }
 
-// Local locker is always online.
+// IsOnline - local locker is always online.
 func (l *localLocker) IsOnline() bool {
 	return true
 }
 
+// IsLocal - local locker returns true.
+func (l *localLocker) IsLocal() bool {
+	return true
+}
+
 func (l *localLocker) Expired(ctx context.Context, args dsync.LockArgs) (expired bool, err error) {
 	select {
 	case <-ctx.Done():