Changes all cases of update_icons(), updateicon(), UpdateIcon() etc. to update_icon(). (#9432)

update_icons(), UpdateIcon() and updateicon() are now changed to be update_icon().

Many interactions expect a target to have an update_icon(), so they should all be the same.

Also fixed some stuff that was using relative pathing, along the way.

code/modules/modular_computers/file_system/programs/research/ai_restorer.dm

@@ -71,7 +71,7 @@
 		A.lying = FALSE
 		A.switch_from_dead_to_living_mob_list()
 		A.add_ai_verbs()
-		A.updateicon()
+		A.update_icon()
 		var/obj/item/aicard/AC = A.loc
 		if(AC)
 			AC.update_icon()