Make payload blocks run onDestroyed() of the block payload it carries when destroyed. (#8253)

* Payloads go boom.

* When a payload unit dies too

* Keep the functionality, but limit it to a rule

core/assets/bundles/bundle.properties

@@ -1313,6 +1313,7 @@ rules.unitdamagemultiplier = Unit Damage Multiplier
 rules.unitcrashdamagemultiplier = Unit Crash Damage Multiplier
 rules.solarmultiplier = Solar Power Multiplier
 rules.unitcapvariable = Cores Contribute To Unit Cap
+rules.unitpayloadsexplode = Carried Payloads Explode With The Unit
 rules.unitcap = Base Unit Cap
 rules.limitarea = Limit Map Area
 rules.enemycorebuildradius = Enemy Core No-Build Radius:[lightgray] (tiles)