HC detector long initialization

[kaituo]

After a few hours, a detector is still in initialization status. Profile API shows no data, but there is nothing show on Kibana. Action items:

1. why no data message is not shown.
   A: Yizhe said we don't have that for HC detector. But single stream detector has that feature.
2. Consider add init progress. I know the number can go backward, but the pros outweighs the cons. Pavani agrees to this.
   A: We can add entity name for the init progress or just say the progress is for the hottest entity.