Collapses the lying down intent into normal resting. (#21967)

Instead of middle clicking to lie down, you now simply rest. You can
also now do it with your gun in your hand. Removes all code related to
bespoke lying down.

To-do:

- [x] Add a signal to make firearm accuracies update on lying down.

---------

Co-authored-by: Matt Atlas <liermattia@gmail.com>

code/modules/projectiles/gun.dm

@@ -908,6 +908,9 @@
 		var/mob/living/living_user = user
 		living_user.stop_aiming(src)
 
+	// so that mobs don't rest with the gun already wielded to bypass the firing delay updates
+	UnregisterSignal(user, COMSIG_MOB_RESTED)
+
 	queue_icon_update()
 	//Unwields the item when dropped, deletes the offhand
 	update_maptext()
@@ -922,6 +925,8 @@
 	..()
 	queue_icon_update()
 	addtimer(CALLBACK(src, PROC_REF(update_maptext)), 1)
+	// so that mobs don't rest with the gun already wielded to bypass the firing delay updates
+	RegisterSignal(user, COMSIG_MOB_RESTED, PROC_REF(update_firing_delays))
 	if(is_wieldable)
 		unwield()