Makes EMP logs less bad (#93841)

## About The Pull Request

closes #93805

## Why It's Good For The Game

we actually have almost no emp logging at all lol, not even emp chem
reaction, so you barely can track potential griefer?

## Changelog

🆑
admin: EMP logs are improved, additionally chemical EMP reactions are
now logged.
/🆑

code/modules/antagonists/changeling/powers/shriek.dm

@@ -44,7 +44,7 @@
 	if(user.movement_type & VENTCRAWLING)
 		user.balloon_alert(user, "can't shriek in pipes!")
 		return FALSE
-	empulse(get_turf(user), 2, 5, 1)
+	empulse(get_turf(user), 2, 5, 1, emp_source = src)
 	for(var/obj/machinery/light/L in range(5, usr))
 		L.on = TRUE
 		L.break_light_tube()

code/modules/antagonists/cult/blood_magic.dm

@@ -183,7 +183,7 @@
 	owner.whisper(invocation, language = /datum/language/common, forced = "cult invocation")
 	owner.visible_message(span_warning("[owner]'s hand flashes a bright blue!"), \
 		span_cult_italic("You speak the cursed words, emitting an EMP blast from your hand."))
-	empulse(owner, 2, 5)
+	empulse(owner, 2, 5, emp_source = src)
 	charges--
 	SSblackbox.record_feedback("tally", "cult_spell_invoke", 1, "[name]")
 	if(charges <= 0)

code/modules/antagonists/cult/runes.dm

@@ -1148,7 +1148,7 @@ GLOBAL_VAR_INIT(narsie_summon_count, 0)
 
 	for(var/mob/living/target in range(src, 3))
 		target.Paralyze(30)
-	empulse(T, 0.42*(intensity), 1)
+	empulse(T, 0.42*(intensity), 1, emp_source = src)
 
 	var/list/images = list()
 	for(var/mob/living/M in GLOB.alive_mob_list)

code/modules/antagonists/wizard/grand_ritual/grand_side_effect.dm

@@ -123,7 +123,7 @@
 /datum/grand_side_effect/emp/trigger(potency, turf/ritual_location, mob/invoker)
 	var/heavy = LERP(0, 3, potency/GRAND_RITUAL_FINALE_COUNT)
 	var/light = LERP(3, 6, potency/GRAND_RITUAL_FINALE_COUNT)
-	empulse(ritual_location, heavy, light)
+	empulse(ritual_location, heavy, light, emp_source = src)
 
 /// Swap locations of nearby mobs arbitrarily and confuse them
 /datum/grand_side_effect/translocate