Cloak, Selected, Construction CUS Round 2

[Beherith]

Fixed shadows off case.

Important note:

Since this partly continues to support engine shaders (CUS OFF) for potatoes, I have decided not to re-add the widgets that use the old HighlightUnit API (mouseover highlight, selection highlight, construction highlight). If they cant run CUS, they shouldn't be using that API either. I am also not readding the LUPS based cloak effect for potatoes either. They get the basic engine transparency effect.

Done:

• [x] Fix rendering when shadows are off
• [x] Fix fallback path when CUS is off

[Beherith]

@Jazcash I would appreciate a quick test, if you'd please.

[Jazcash]

Looks like

👍

[Damgam]

Tested, LGTM