LibWebView: Add method to break a URL into parts for eTLD+1 highlighting

This is meant to serve as the method all Ladybird chromes can use to
highlight the eTLD+1 substring of the URL. It uses the Public Suffix
List to break the URL into 3 parts: the scheme and subdomain, the
eTLD+1, and all remaining parts (port, path, query, etc.).

Userland/Libraries/LibWebView/URL.h

@@ -16,7 +16,13 @@ enum class AppendTLD {
     No,
     Yes,
 };
-
 Optional<URL> sanitize_url(StringView, Optional<StringView> search_engine = {}, AppendTLD = AppendTLD::No);
 
+struct URLParts {
+    StringView scheme_and_subdomain;
+    StringView effective_tld_plus_one;
+    StringView remainder;
+};
+Optional<URLParts> break_url_into_parts(StringView url);
+
 }