Improvements to groups and UI

[Monsterovich]

Summary of this PR:

• The droid count is now refreshed immediately when units retreat for repair.
• Added a display of the number of damaged units in the group that will return to it after repair. This is also important information. For example: sometimes you forget about damaged units and they just stay at HQ (forgot to build a repair facility, lost all repairing units, etc.).
• Now a group of damaged units is not recovered until the units are fully repaired, as it was intended in the original PR. Exception: if you set their repair flag to "do or die".
• Improved the display of unit count text inside the widget. The three digit number was exceeding the borders of the widget. Now all variations are displayed correctly.

[KJeff01]

Pastdue and I are uncertain about the purpose of this change. The intent for this if statement was to prevent a retreating unit, that was disturbed from rtr/rtb, forever having a red group number until fully repaired. Unless there is some specific behavior difference we aren't noticing.

[Monsterovich]

@KJeff01

forever having a red group number until fully repaired. Unless there is some specific behavior difference we aren't noticing.

This is only possible if there are no repair facilities or repairing units.

In the worst case, I'll just set a "do or die" flag on the units and just send them into battle, but it's too expensive to lose units. That's what alfred007 was talking about on Discord:

The point is to keep as many units as possible, at the very least let them stand at the HQ with repair group set until I build repair facilities and send them to be repaired. Currently, the damaged units will just go into battle with low health which is worse.

[Monsterovich]

There is also an idea to make damaged units that stand at the HQ, automatically go to repair when at least one repair facility appears (I can do this, but it would be in a separate PR).