Ability to view object health in spectator/replay mode

[DARwins1]

Describe the bug
When watching a game as a spectator, or reviewing a game in replay mode, it is impossible to see the health bar of units/structures by holding down right click, as you would in normal gameplay.

To Reproduce
Steps to reproduce the behavior:

1. Enter a game as a spectator (either by joining a multiplayer game as a spectator, or by watching a skirmish/MP replay)
2. Hold down right click on any unit or structure
3. Notice how nothing happens

Expected behavior
Holding down right click on any unit or structure should display its health bar, just like during normal gameplay.

Your System:

• OS: Windows 10
• Game version: 4.2.0-beta2

[past-due]

This is a known limitation of the current implementation (some more refactoring is needed to handle this properly for spectators).