Reworked electrocute_act to fit my fantasy while squashing some bugs. (#45291)

* Reworked electrocute_act
This still isn't perfect, ideally this would use flags and stuff but I don't have the energy for a change of that size.

* Removes spec_electrocute_act and makes the species siemens_coeff actually work.

* Readds the secondary shock

code/modules/reagents/chemistry/reagents/pyrotechnic_reagents.dm

@@ -217,6 +217,18 @@
 		playsound(M, "sparks", 50, 1)
 	..()
 
+/datum/reagent/teslium/on_mob_metabolize(mob/living/carbon/human/L)
+	. = ..()
+	if(!istype(L))
+		return
+	L.physiology.siemens_coeff *= 2
+
+/datum/reagent/teslium/on_mob_end_metabolize(mob/living/carbon/human/L)
+	. = ..()
+	if(!istype(L))
+		return
+	L.physiology.siemens_coeff *= 0.5
+
 /datum/reagent/teslium/energized_jelly
 	name = "Energized Jelly"
 	description = "Electrically-charged jelly. Boosts jellypeople's nervous system, but only shocks other lifeforms."