LibJS: Implement Temporal.TimeZone.prototype.id

Author: https://github.com/linusg
Commit: 51c581f604
Pull-request: https://github.com/SerenityOS/serenity/pull/8568
Reviewed-by: https://github.com/IdanHo
Reviewed-by: https://github.com/bgianfo ✅

Userland/Libraries/LibJS/Tests/builtins/Temporal/TimeZone/TimeZone.prototype.id.js

@@ -0,0 +1,10 @@
+describe("correct behavior", () => {
+    test("basic functionality", () => {
+        const timeZone = new Temporal.TimeZone("UTC");
+        expect(timeZone.id).toBe("UTC");
+    });
+
+    test("works with any this value", () => {
+        expect(Reflect.get(Temporal.TimeZone.prototype, "id", "foo")).toBe("foo");
+    });
+});