feat: allow using String.prototype.includes in item effect filters

src/expression-evaluation/evaluator.ts

@@ -19,7 +19,7 @@ export class Evaluator<Context extends object> {
         get: (t, k) => (k === Symbol.unscopables ? undefined : t[k as keyof typeof t]),
       });
       actualPredicate = (identifier: string) =>
-        predicate(identifier) || Object.getOwnPropertyNames(Math).includes(identifier);
+        predicate(identifier) || Object.getOwnPropertyNames(context).includes(identifier);
     }
     this.validator = new Validator(actualPredicate);
   }