Improve fireball enchantment and fire-related effects/interactions

Description of changes

Makes fake fire effects use the same logic as real fire for color, light, etc.
Makes scorched grass a separate turf type than normal grass, to fix issues with edges.
Generalizes mob fire/burning logic to mob/living.
Dramatically increases grass scorching chance because honestly, it was way too rare. Also, it's now based on material properties.
Allows projectiles to hit objects on STRUCTURE_LAYER such as campfires.
Improves projectile handling when mimic turfs are targeted.
Completely redoes the fireball enchantment to use a custom projectile that spawns a fake_fire effect, since the previous one didn't work and even when I fixed it, all it did was cause an explosion.

Makes the fireball effect more fun to use, and you can even use it to light campfires!