Add ability for +VVEDIT users to scale damage/healing in the game (#35255)

* Initial commit

* Add universal modifier for all damage/heals, make guidebooks work.

* help text

Content.Server/Explosion/EntitySystems/ExplosionSystem.Processing.cs

@@ -464,7 +464,7 @@ public sealed partial class ExplosionSystem
                 }
 
                 // TODO EXPLOSIONS turn explosions into entities, and pass the the entity in as the damage origin.
-                _damageableSystem.TryChangeDamage(entity, damage, ignoreResistances: true);
+                _damageableSystem.TryChangeDamage(entity, damage * _damageableSystem.UniversalExplosionDamageModifier, ignoreResistances: true);
 
             }
         }