Greimorian Egg Cluster Implantation Refactor (#21554)

Fixes https://github.com/Aurorastation/Aurora.3/issues/21509

**Summary:**
Cleans up a lot of old Greimorian egg implantation code- rewrote the
actual worker injection behavior to use the organ/internal/parasite code
we have, instead of creating effects with their loc set to the organ
itself.

This largely means that not only is Greimorian implantation able to be
treated pharmaceutically (as you'd expect, with them being parasitic and
medicine including antiparasitics), but it also means that 'greimorian
eggs' also get the same treatment as nerve flukes, etc. That is to say,
antags can now purchase Greimorian Clade Kits from the uplink and inject
people or monkeys with them to cause Unhappy Tidings.

This code is also fairly easy to modify, if one wanted to create more
implantable parasites that burst out of people, unrelated to
Greimorians.

**Changes:**
- refactor: "Refactors the egg injection of Greimorian Workers to use
parasite code; it can now be treated with anti-parasitic medicines in
addition to amputation of the affected limb. Works on all playable
species, and monkeys."
- rscadd: "New reagent 'Greimorian Eggs' creates an egg cluster parasite
in a random organ when metabolized in the bloodstream. It also has very
mild soporific effects."
- balance: "Greimorian Workers and playable Greimorian Servants/Queen
now inject Greimorian Eggs instead of Soporific."
- rscadd: "Greimorian Clade Kit now available in Uplink under Bioweapons
section (Greimorians now able to be introduced to ship by egg cluster or
injectable reagent)."
- balance: "All parasite kit bioweapons have had their vial reagent
count increased from 2 -> 5."
- balance: "Helmizole no longer treats K'ois Mycosis, Black K'ois
Mycosis, Zombification, or Tumors (Benign or Malignant)."
  - code_imp: "Updates a lot of code documentation to dmdocs."

code/modules/reagents/Chemistry-Reagents/Chemistry-Reagents-Medicine.dm

@@ -2015,13 +2015,12 @@
 		M.add_chemical_effect(CE_EMETIC, M.chem_doses[type]/2)
 
 /singleton/reagent/antiparasitic/overdose(mob/living/carbon/M, alien, removed, scale, datum/reagents/holder)
-	if(istype(M,/mob/living/carbon/human))
-		var/mob/living/carbon/human/H = M
-
-		for(var/obj/item/organ/internal/parasite/P in H.internal_organs)
-			if(P)
-				if(P.drug_resistance == 0)
-					P.drug_resistance = 1
+	M.dizziness = max(50, M.dizziness)
+	M.make_dizzy(5)
+	M.adjustHydrationLoss(2*removed)
+	M.adjustNutritionLoss(8*removed)
+	M.adjustHalLoss(5)
+	to_chat(M, SPAN_WARNING(pick("You feel flushed and woozy.", "Your guts feel like they're crawling.")))
 
 /singleton/reagent/antibodies
 	name = "Hylemnomil-Zeta Antibodies"

code/modules/reagents/Chemistry-Reagents/Chemistry-Reagents-Toxins.dm

@@ -1029,6 +1029,44 @@
 			var/obj/item/organ/internal/parasite/heartworm/infest = new()
 			infest.replaced(H, affected)
 
+/// Functions as a weaker version of soporific and also infests the victim with eggs.
+/singleton/reagent/toxin/greimorian_eggs
+	name = "Greimorian Eggs"
+	description = "The eggs of a greimorian clade. They are highly opportunistic, capable of infesting almost any organism, and are feared for the relatively swift speed with which they gestate. Immediate surgical removal or pharmaceutical intervention is a vital necessity."
+	reagent_state = SOLID
+	color = "#5f683f"
+	metabolism = REM*2
+	ingest_met = REM*2
+	touch_met = REM*5
+	taste_description = "something noxious"
+	taste_mult = 0.25
+	strength = 0
+
+/singleton/reagent/toxin/greimorian_eggs/affect_blood(mob/living/carbon/mob, alien, removed, datum/reagents/holder)
+	..()
+	if(istype(mob,/mob/living/carbon/human))
+		var/mob/living/carbon/human/victim = mob
+
+		victim.add_chemical_effect(CE_PULSE, -2)
+		var/dose = victim.chem_doses[type]
+		if(dose > 2)
+			if(ishuman(victim) && (dose == metabolism * 2 || prob(3)))
+				victim.emote("yawn")
+		if(dose > 20)
+			victim.eye_blurry = max(victim.eye_blurry, 10)
+		if(dose > 40)
+			victim.Weaken(1)
+			victim.drowsiness = max(victim.drowsiness, 20)
+
+		if(victim.chem_effects[CE_ANTIPARASITE])
+			return
+
+		if(!victim.internal_organs_by_name[BP_GREIMORIAN_EGGCLUSTER])
+			var/obj/item/organ/external/affected = pick(victim.organs)
+			var/obj/item/organ/internal/parasite/greimorian_eggcluster/infest = new()
+			infest.parent_organ = affected.limb_name
+			infest.replaced(victim, affected)
+
 /singleton/reagent/toxin/malignant_tumour_cells
 	name = "Malignant Tumour Cells"
 	description = "Cells of a malignant tumour which have broken off and entered the circulatory and/or lymphatic system to spread to other regions of the body."