Port initial Bay12 object listener fix (#2106)

Port of Baystation12/Baystation12#13264

Large PR to put into Master, but the bug is really annoying and since it affect a traitor item, an often used one, I'll take the risk.

Fixes #1956
Fixes explosives implants and lawgiver not working.

code/modules/assembly/holder.dm

@@ -211,6 +211,15 @@
 		return 1
 
 
+/obj/item/device/assembly_holder/New()
+	..()
+	listening_objects += src
+
+/obj/item/device/assembly_holder/Destroy()
+	listening_objects -= src
+	return ..()
+	
+
 /obj/item/device/assembly_holder/hear_talk(mob/living/M as mob, msg, verb, datum/language/speaking)
 	if(a_right)
 		a_right.hear_talk(M,msg,verb,speaking)

code/modules/assembly/voice.dm

@@ -7,6 +7,14 @@
 	var/listening = 0
 	var/recorded	//the activation message
 
+/obj/item/device/assembly/voice/New()
+	..()
+	listening_objects += src
+
+/obj/item/device/assembly/voice/Destroy()
+	listening_objects -= src
+	return ..()
+
 /obj/item/device/assembly/voice/hear_talk(mob/living/M as mob, msg)
 	if(listening)
 		recorded = msg
@@ -33,4 +41,4 @@
 
 /obj/item/device/assembly/voice/toggle_secure()
 	. = ..()
-	listening = 0
+	listening = 0