Refactors chicks into basic mobs (#75663)

## About The Pull Request

On the tin. They have pretty much nothing in common with chickens, so no
subtyping. They are in the same folder to keep that whole thing tidy,
though.

Also includes fixes to `growth_and_differentiation` element that I made
for spiderlings, since some stuff was yorked without me realizing. It
pretty much worked flawlessly for these chicks otherwise though. It all
works fine now.
## Why It's Good For The Game

More verbose naming scheme (instead of "holo", we get "permanent"
chicks), smarter AI for chicks, knocks them off the list, etc. etc.

One thing that I wanted to do was to have chicks recognize their mother
(if they had one), but that would be way out of scope for this simple
port PR. I'll dwell on adding something cool for that in the future.
## Changelog
🆑
refactor: Chicks are now a bit smarter, be careful not to squish them!
/🆑

Let me know if the whole "COMPONENT_KILL" thing is cringe, I couldn't
figure out a better way to do it without abusing `GetComponent()` to
`qdel()` it that way.

code/datums/ai/basic_mobs/basic_subtrees/speech_subtree.dm

@@ -96,6 +96,12 @@
 	emote_hear = list("clucks.", "croons.")
 	emote_see = list("pecks at the ground.","flaps her wings viciously.")
 
+/datum/ai_planning_subtree/random_speech/chick
+	speech_chance = 4
+	speak = list("Cherp.", "Cherp?", "Chirrup.", "Cheep!")
+	emote_hear = list("cheeps.")
+	emote_see = list("pecks at the ground.","flaps her tiny wings.")
+
 /datum/ai_planning_subtree/random_speech/cow
 	speech_chance = 1
 	speak = list("moo?","moo","MOOOOOO")