Negative trait point changes. (#18509)

Changed some of the negative traits point values, primarily as they give so many points relative to the small cost of positive traits:
Low Blood Volume from 3 to 2 and the extreme version from 5 to 3. These are serious, but they're reasonably in-line with other serious weakness traits.
Reduced biocompatibility 2->1, 4->2, 8->4. These are really not that much of an issue, if you are in medbay getting treated, it just means they need to stick you with a couple extra syringes and rarely actually causes a problem other than taking a couple more minutes. 4 points is still a lot.
Ambulant Blood 1 to 0, this has no effect at all here where changelings are never a risk.

code/modules/mob/living/carbon/human/species/station/traits/negative.dm

@@ -244,7 +244,7 @@
 /datum/trait/negative/less_blood
 	name = "Low Blood Volume"
 	desc = "You have 33.3% less blood volume compared to most species, making you more prone to blood loss issues."
-	cost = -3
+	cost = -2
 	var_changes = list("blood_volume" = 375)
 	excludes = list(/datum/trait/negative/less_blood_extreme)
 	can_take = ORGANICS
@@ -252,7 +252,7 @@
 /datum/trait/negative/less_blood_extreme
 	name = "Low Blood Volume, Extreme"
 	desc = "You have 60% less blood volume compared to most species, making you much more prone to blood loss issues."
-	cost = -5
+	cost = -3
 	var_changes = list("blood_volume" = 224)
 	excludes = list(/datum/trait/negative/less_blood)
 	can_take = ORGANICS
@@ -601,21 +601,21 @@
 /datum/trait/negative/reduced_biocompat_minor
 	name = "Reduced Biocompatibility, Minor"
 	desc = "For whatever reason, you're one of the unlucky few who don't get as much benefit from modern-day chemicals. Remember to note this down in your medical records! Chems are only 80% as effective on you!"
-	cost = -2
+	cost = -1
 	var_changes = list("chem_strength_heal" = 0.8)
 	can_take = ORGANICS
 
 /datum/trait/negative/reduced_biocompat
 	name = "Reduced Biocompatibility"
 	desc = "For whatever reason, you're one of the unlucky few who don't get as much benefit from modern-day chemicals. Remember to note this down in your medical records! Chems are only 60% as effective on you!"
-	cost = -4
+	cost = -2
 	var_changes = list("chem_strength_heal" = 0.6)
 	can_take = ORGANICS
 
 /datum/trait/negative/reduced_biocompat_extreme
 	name = "Reduced Biocompatibility, Major"
 	desc = "For whatever reason, you're one of the unlucky few who don't get as much benefit from modern-day chemicals. Remember to note this down in your medical records! Chems are only 30% as effective on you!"
-	cost = -8
+	cost = -4
 	var_changes = list("chem_strength_heal" = 0.3)
 	can_take = ORGANICS
 

code/modules/mob/living/carbon/human/species/station/traits/negative_genes.dm

@@ -202,7 +202,7 @@
 	name = "Ambulant Blood"
 	desc = "Your blood reacts to hostile stimulation such as burning when seperated from your body, as if it was its own creature. You WILL be mistaken for a changeling, you may want to document this in your medical records."
 	var_changes = list("ambulant_blood" = TRUE)
-	cost = -1
+	cost = 0
 
 	is_genetrait = TRUE
 	hidden = FALSE