further bootstrap/startup optimization for reading 'format.json' (#18868)

- Move RenameFile to websockets
- Move ReadAll that is primarily is used
  for reading 'format.json' to to websockets
- Optimize DiskInfo calls, and provide a way
  to make a NoOp DiskInfo call.

cmd/global-heal.go

@@ -156,7 +156,7 @@ func (er *erasureObjects) healErasureSet(ctx context.Context, buckets []string,
 		}
 	}
 
-	info, err := tracker.disk.DiskInfo(ctx, false)
+	info, err := tracker.disk.DiskInfo(ctx, DiskInfoOptions{})
 	if err != nil {
 		return fmt.Errorf("unable to get disk information before healing it: %w", err)
 	}