EjectOnDeath - updated and 100% working

I am very thankful to the great people of this community for spending hours to teach me many new things and I know I have much more to discover, so expect many more annoying nights. ;)

EjectOnDeath original PR: https://github.com/OpenRA/OpenRA/pull/3922

Updated EjectOnDeath:
• Works the exact same way for people using only .yaml to make mods

```yaml
UNIT:	
	EjectOnDeath:
		PilotActor: e1
		SuccessRate: 20
```

• Internally there are 2 versions.

    º Version 1: All code contained in OpenRA.Mods.RA/EjectOnDeath.cs
        (except yaml values: mods/ra/rules/defaults.yaml - example above)

    º Version 2: Crafted by pchote, changes 4 files (along with EjectOnDeath.cs):
        ˚ OpenRA.Game/Traits/TraitsInterfaces.cs
        ˚ OpenRA.Mods.RA/Air/Aircraft.cs
        ˚ OpenRA.Mods.RA/Crate.cs
        ˚ OpenRA.Mods.RA/Husk.cs

• EjectOnDeath.cs was moved from Mods.RA/Air to the root of Mods.RA because it no longer only applies to aircraft.