LibWeb: Implement HTMLSelectElement.type

Author: https://github.com/Lubrsi
Commit: c4ee43c5b4
Pull-request: https://github.com/SerenityOS/serenity/pull/15964
Reviewed-by: https://github.com/awesomekling

Userland/Libraries/LibWeb/HTML/HTMLSelectElement.h

@@ -56,6 +56,8 @@ public:
     // https://html.spec.whatwg.org/multipage/forms.html#category-label
     virtual bool is_labelable() const override { return true; }
 
+    String const& type() const;
+
 private:
     HTMLSelectElement(DOM::Document&, DOM::QualifiedName);