Implemented Union Types in GraphQL (#3852)

* Fetch correct amount of data

* Allow system required data to be returned in items service

* Fetch non-requested required data, find type through context

Fixes #3718

api/src/controllers/graphql.ts

@@ -13,6 +13,7 @@ router.use(
 			accountability: req.accountability,
 			schema: req.schema,
 		});
+
 		const schema = await service.getSchema();
 
 		/**