Add "animaltrap-reuse" tweak

[quietust]

Makes it so animal traps generate "Release Small Creature" jobs instead of "Destroy Building" jobs, so a dwarf will transfer the caught vermin into an empty stockpiled trap and leave the built trap ready to be automatically filled with new bait (similar to how standard Cage Traps work).

The only downside is that if you don't have any empty animal traps in your stockpiles, you will get an endless stream of "Release Small Creature" job cancellations, but the exact same thing happens if you unassign a vermin from a built cage so it's probably fine (and you can still schedule the animal trap for deconstruction).

In order to make the "Release Small Creature" job work correctly, the caught vermin needs to be simultaneously added to both the building inventory and the animal trap itself, but fortunately the game appears to handle this scenario gracefully - whether the "Release Small Creature" job finishes or the building gets deconstructed, all of the references get correctly cleaned up, and saving/loading does not appear to break any of the links either.

[quietust]

Built animal traps have a "reload timer" which they use for adding bait; in theory, we could reuse this to also space out "release creature" jobs to reduce cancellation spam when no traps are available (but we would probably need to restore it to a sane value afterwards so the trap still gets re-baited in a timely manner).