Dog wit the butter (feat. a bunch of dog-related code improvements) (#77039)

## About The Pull Request
Adds a `dog_fashion` for the stick of butter.(screenshot is outdated as
Lisa won't have butter no more)
![butter
dawgs](https://github.com/tgstation/tgstation/assets/75863639/a22e702c-98a8-4283-abd9-28d4a9fb3bd0)

Also cleans up dog.dm because it was SHIT and FUCK and MY FUCKING GOD
TWO INITIALIZE()s TWO TIMES IN A SINGLE FILE WHAT IN THE GODDAMN

Most noticeably, Lisa properly won't wear any hats, and puppies properly
can't wear head/back items (by just removing those item slots from the
strip/equip menu. if some admeme wants to fumble around they may still
equip shit there. but otherwise for a normal player those slots are
inaccessible).
Basic mobs now also send signals when they run
`appear_dead`/`appear_alive` procs, which corgis hook into to update
their dead fashion overlays.
The side-effect of getting that to work is that dogs (and any basic mob
that uses `play_dead` ai behavior) are so good at feigning death, that
they fool medical HUDs and other related things. They're just that good.
There's a bunch of other things involved and I was mostly just being
angry at the state of the file so I'll check back when I gather all
things changed.


![strippy](https://github.com/tgstation/tgstation/assets/75863639/ec4d17a2-d4df-401c-bd1f-7c4ee1b95671)


## Why It's Good For The Game


https://github.com/tgstation/tgstation/assets/75863639/b34589cb-94d6-4b80-bf0f-1814c08da100



## Changelog
🆑
add: dog with a butter on 'em
add: dead dog with da butter on 'em (dogs feigning death are so good at
it, they appear dead to medical HUDs and other things)
add: Nars-Ian now can revive from the dead if he consumes a pet
fix: fixes dog fashion items with no speech modifiers set making dressed
up corgis unable to perform their speech or emote behaviors
fix: fixes old Ian losing his mobility ride when shaved with a razor
fix: fixes pets not dropping their collar when gibbed
fix: butter don't go on Lisa and corgi puppies (Lisa won't wear hats and
corgi puppies can't wear hats and back slot items)
/🆑

code/datums/ai/basic_mobs/pet_commands/play_dead.dm

@@ -7,6 +7,7 @@
 	if(!istype(basic_pawn) || basic_pawn.stat) // Can't act dead if you're dead
 		return
 	basic_pawn.emote("deathgasp", intentional=FALSE)
+	ADD_TRAIT(basic_pawn, TRAIT_FAKEDEATH, BASIC_MOB_DEATH_TRAIT)
 	basic_pawn.look_dead()
 
 /datum/ai_behavior/play_dead/perform(seconds_per_tick, datum/ai_controller/controller)
@@ -20,5 +21,6 @@
 	if(!istype(basic_pawn) || basic_pawn.stat) // imagine actually dying while playing dead. hell, imagine being the kid waiting for your pup to get back up :(
 		return
 	basic_pawn.visible_message(span_notice("[basic_pawn] miraculously springs back to life!"))
+	REMOVE_TRAIT(basic_pawn, TRAIT_FAKEDEATH, BASIC_MOB_DEATH_TRAIT)
 	basic_pawn.look_alive()
 	controller.clear_blackboard_key(BB_ACTIVE_PET_COMMAND)