Adds the bloodroach (#91383)

## About The Pull Request

Adds bloodroaches.


![image](https://github.com/user-attachments/assets/2f122787-0a22-4ff3-9c9b-7e14ca479369)

These are cockroaches that have gorged themselves on blood in
maintenance. They're very gross!


![image](https://github.com/user-attachments/assets/1ff744ed-a61b-4f6b-8d1c-28664f7a953f)

Splatting one causes an explosion of blood all around the death
perimeter, splashing both turfs and mobs with blood.

They have a 1% chance of spawning in place of normal roaches.

They also spawn in:
- Abandoned crates, replacing the 30 roaches with 30 bloodroaches.
- As backup anomalous crystal possession targets.
- Grimy fridges

Added a trait given to things killed by pest spray, used to check on
death explosion for bloodroaches.
Changed roach spawns in maps to use mob spawners, so I can replace them
with bloodroaches 1% of the time.
## Why It's Good For The Game

Splatting a random roach in maintenance that explodes into blood sounds
hilarious. It also adds janitorial depth by requiring pest spray to
carefully eliminate these pests
## Changelog
🆑
add: Added bloodroaches, a rare variant of cockroaches that explode into
a shower of blood when squashed.
/🆑

code/game/objects/effects/spawners/random/trash.dm

@@ -162,6 +162,7 @@
 	loot = list( // This spawner will scatter garbage around a dirty site.
 		/obj/effect/spawner/random/trash/garbage = 6,
 		/mob/living/basic/cockroach = 5,
+		/mob/living/basic/cockroach/bloodroach = 1,
 		/obj/effect/decal/cleanable/garbage = 4,
 		/obj/effect/decal/cleanable/vomit/old = 3,
 		/obj/effect/spawner/random/trash/cigbutt = 2,
@@ -171,7 +172,7 @@
 	if(mapload)
 		var/turf/location = get_turf(loc)
 		if(location.initial_gas_mix != OPENTURF_DEFAULT_ATMOS && location.initial_gas_mix != OPENTURF_DIRTY_ATMOS)
-			loot -= /mob/living/basic/cockroach
+			loot -= list(/mob/living/basic/cockroach, /mob/living/basic/cockroach/bloodroach)
 	return ..()
 
 /obj/effect/spawner/random/trash/moisture