Add a "create-ghost" CreateEntityTriggerEffectItem

[kelianmao]

Would it be possible to add a field for ghost_name / inner_name for the CreateEntityTriggerEffectItem trigger, so we can use it to create "entity-ghost"s? Or maybe a subclass "create-ghost", like "create-fire" etc

I'm trying to make an entity create a ghost of a different entity upon death. And while it does seem possible with an on_entity_died listener that calls create_entity, this would be in Lua and (probably) less efficient than using prototypes/triggers in the data stage.

Thanks!