Tests/LibWeb: Add standard built-in objects test for structuredClone()

Author: https://github.com/kennethmyhra
Commit: https://github.com/SerenityOS/serenity/commit/66c0e78c7d
Pull-request: https://github.com/SerenityOS/serenity/pull/20247

Tests/LibWeb/Text/expected/HTML/StructuredClone-object-primitives.txt

@@ -0,0 +1,6 @@
+true
+false
+123
+123.456
+This is a String object
+1692748800000

Tests/LibWeb/Text/input/HTML/StructuredClone-object-primitives.html

@@ -0,0 +1,11 @@
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        println(structuredClone(new Boolean(true)));
+        println(structuredClone(new Boolean(false)));
+        println(structuredClone(new Number(123)));
+        println(structuredClone(new Number(123.456)));
+        println(structuredClone(new String("This is a String object")));
+        println(structuredClone(Date.UTC(2023, 7, 23)));
+    });
+</script>