Cuts the number of apply_damage copypaste procs from 3(.5) to 1, fixing a few bugs along the way (#79207)

## About The Pull Request

- `apply_damage` is now uniform, handled, in a single place. At the
living level.
- Fixes people being held at gunpoint from being unable to flinch from
taking damage.
- Fixes a few signals (explodable, glass jaw) of apply damage maybe
potentially not having effects if the passed hit zone was a bodypart and
not a def zone.
- Fixes regenerator component always halting regeneration no matter what
damage taken.
- Fixes pressure damage being unaffected by `brute_mod` despite what
documentation claims.
- Signalizes the `check_species_weakness` proc on species. 

## Why It's Good For The Game

The copy+paste of this proc made it awful, awful to maintain or add
features to. And also made it very bug prone.

This just takes a step forward in making sustaining damage a lot more
consistent, not only across all mobs, but across all methods of...
taking damage. Unarmed attacks, hulk, item attacks, etc.

## Changelog

🆑 Melbert
fix: People held at gunpoint can now flinch when being hit. 
fix: Regenerating mobs no longer stop regenerating no matter hit with
what.
fix: Pressure damage is now properly modified by a mob's brute damage
modifier.
fix: Fixes some occasions which some effects (glass jaw, explodable worn
items) won't respond to hits.
refactor: Refactored core code related to mobs sustaining damage. 
/🆑

code/modules/bitrunning/server/util.dm

@@ -58,10 +58,10 @@
 			"health" = creature.health,
 			"name" = creature.name,
 			"pilot" = pilot,
-			"brute" = creature.get_current_damage_of_type(BRUTE),
-			"burn" = creature.get_current_damage_of_type(BURN),
-			"tox" = creature.get_current_damage_of_type(TOX),
-			"oxy" = creature.get_current_damage_of_type(OXY),
+			"brute" = creature.getBruteLoss(),
+			"burn" = creature.getFireLoss(),
+			"tox" = creature.getToxLoss(),
+			"oxy" = creature.getOxyLoss(),
 		))
 
 	return hosted_avatars