LibWeb: Add Support for the ARIA Element Properties

Element now supports getting and setting ARIA properties from
JS and HTML.

Userland/Libraries/LibWeb/HTML/HTMLAreaElement.h

@@ -39,6 +39,8 @@ private:
     {
         queue_an_element_task(source, move(steps));
     }
+
+    virtual FlyString default_role() const override;
 };
 
 }