AK+LibUnicode: Add Unicode::create_unicode_url

This is a workaround for the fact that AK::URLParser can't call into
LibUnicode directly.

Userland/Libraries/LibUnicode/URL.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2023, Simon Wanner <simon@skyrising.xyz>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/String.h>
+#include <AK/URL.h>
+
+namespace Unicode {
+
+ErrorOr<URL> create_unicode_url(String const&);
+
+}