EgwApp object need to be global / assigned to window.EgwApp

as that's how we iterate through all EgwApp instances for observer and push

api/js/jsapi/egw_app.ts

@@ -2262,3 +2262,5 @@ export abstract class EgwApp
 		return EgwApp._instances[Symbol.iterator]();
 	}
 }
+// EgwApp need to be global on window, as it's used to iterate through all EgwApp instances
+window.EgwApp = EgwApp;