Add a "harvest" butchering option

Add a new “harvest” butchering option. This is for when you are butchering and just trying to aquire materials not edible food. This would make sense for things like zombies. Your survivor probably wouldn’t focus on the meat of zombies as it is useless to them and instead focus exclusively on cutting out the fat and bones. The same goes for mutants. I could see a survivor mass mudering mutants purely to cut them up for their fat, bones/chitin and skin. This could save you a lot of time when you are trying to cut up and turn zombies into tallow before the fat rots away.

Maybe there should even be options for the specific part you are trying to harvest. Just like we have skinning to specifically harvest the skin of a creature, maybe we could have something similar for fat and bones. Harvesting specifically bones or chitin could be done very fast as these are hard things so you could simply cut/chop of the softer bits without having to be carefull or precise. Harvesting fat would be a bit slower but would still be useful when you are just trying to turn corpses into fuel.