Leanable component (#21431)

Refactors leanable code into a component, now attached to walls, (full)
windows, doors (of all types), and vending machines. See video for
example behavior.

https://github.com/user-attachments/assets/032d2cb2-17e3-4604-90b6-040e183dccd9

code/game/objects/structures/window.dm

@@ -781,6 +781,10 @@
 	qdel(src)
 	update_nearby_icons()
 
+/obj/structure/window/full/mouse_drop_receive(atom/dropping, mob/user, params)
+	//Adds the component only once. We do it here & not in Initialize() because there are tons of walls & we don't want to add to their init times
+	LoadComponent(/datum/component/leanable, dropping)
+
 /********** Full Windows **********/
 // Reinforced Window
 /obj/structure/window/full/reinforced