[New Feature] Harvester counter: flashing when losing Harvester

[TAK02]

I think the counter should flash red when a Harvester unit is lost.

So if the counter is 2/2 and goes down to 1/1 it should flash through Sidebar.HarvesterCounter.ColorYellow= and Sidebar.HarvesterCounter.ColorRed= before it stops at UI's color instead of staying at UI's color or Sidebar.HarvesterCounter.ColorGreen= or something.