Extend production_health_effect support to Generator prototypes

[Malidictus]

I'd like to request extending the "production_health_effect" field from CraftingMachinePrototype to at least GeneratorPrototype, BurnerGeneratorPrototype and FusionGeneratorPrototype. Specifically, I'd like to optionally have generators passively heal or passively take damage over time as they work.

I presume there's a performance reason for why structures disregard their healing_per_tick field, but if production_health_effect can work on crafting machines which are typically built in bulk and run with very high uptime, adding generators into the sounds reasonable to me.

[MrSmoothieHuman]

+1