[CLOSED PR] Replaces most instances of fake corpses with real corpses

[Tarmunora]

Seconding Jan here. having the corpse-spawners for mappers to use on a case-by-case basis is good, but I'm feeling like a mass find-replace of corpse decals is the wrong way to go, both for concerns of introducing unforseen lootables in random places, and that yikes that's a lot of extra mobs to be loading in all the time.