Add [found_item] ConditionalWML that checks if an [object] ActionWML has been taken

changelog

@@ -89,6 +89,7 @@ Version 1.13.1+dev:
        number of movement points the attack consumes
    * Ability to patch movetypes to account for custom terrains or damage types
    * Removed y offset by -1 from [message]'s scroll-to-unit logic.
+   * Add [found_item] ConditionalWML to check if an [object]id= ActionWML has been taken
  * Editor:
    * Added Category field and color sliders to the Edit Label panel.
  * Miscellaneous and bug fixes:

data/lua/wml/object.lua

@@ -78,3 +78,7 @@ function wesnoth.game_events.on_save()
 	table.insert(cfg, T.used_items(used_items) )
 	return cfg
 end
+
+function wesnoth.wml_conditionals.found_item(cfg)
+	return used_items[cfg.id]
+end