LibWeb: Port URL and URLSearchParams to new String

Author: https://github.com/kennethmyhra
Commit: 9da09e4fd3
Pull-request: https://github.com/SerenityOS/serenity/pull/17686
Reviewed-by: https://github.com/linusg

Userland/Libraries/LibWeb/URL/URL.idl

@@ -1,7 +1,7 @@
 #import <URL/URLSearchParams.idl>
 
 // https://url.spec.whatwg.org/#url
-[Exposed=*, LegacyWindowAlias=webkitURL]
+[Exposed=*, LegacyWindowAlias=webkitURL, UseNewAKString]
 interface URL {
     constructor(USVString url, optional USVString base);