Fix paperplanes unfolding into different hand; balloon alerts (#73522)

🆑 coiax
fix: Paper planes when unfolded will put the paper in your active hand,
rather than a different hand, just like cardboard boxes.
/🆑

- Also, use balloon alerts for folded/unfolded to match boxes

## Why It's Good For The Game
Generally when you transform items from one form into another while
having them in your hand, they generally go into the same hand. Also,
people like balloon alerts now for these sorts of very minor
transformations.

code/modules/paperwork/paperplane.dm

@@ -61,12 +61,16 @@
 		. += "paperplane_[stamp]"
 
 /obj/item/paperplane/attack_self(mob/user)
-	to_chat(user, span_notice("You unfold [src]."))
-	// We don't have to qdel the paperplane here; it shall be done once the internal paper object is moved out of src anyway.
-	if(user.Adjacent(internalPaper))
-		user.put_in_hands(internalPaper)
-	else
-		internalPaper.forceMove(loc)
+	balloon_alert(user, "unfolded")
+
+	var/atom/location = drop_location()
+	// Need to keep a reference to the internal paper
+	// when we move it out of the plane, our ref gets set to null
+	var/obj/item/paper/internal_paper = internalPaper
+	internal_paper.forceMove(location)
+	// This will as a side effect, qdel the paper plane, making the user's hands empty
+
+	user.put_in_hands(internal_paper)
 
 /obj/item/paperplane/attackby(obj/item/P, mob/living/carbon/human/user, params)
 	if(burn_paper_product_attackby_check(P, user))
@@ -136,7 +140,7 @@
  * * obj/item/paperplane/plane_type - what it will be folded into (path)
  */
 /obj/item/paper/proc/make_plane(mob/living/user, obj/item/I, obj/item/paperplane/plane_type = /obj/item/paperplane)
-	to_chat(user, span_notice("You fold [src] into the shape of a plane!"))
+	balloon_alert(user, "folded into a plane")
 	user.temporarilyRemoveItemFromInventory(src)
 	I = new plane_type(loc, src)
 	if(user.Adjacent(I))