LibWeb: Implement navigator.clipboard.read

Author: https://github.com/trflynn89
Commit: 912009f6b3
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4548
Reviewed-by: https://github.com/shannonbooth

Libraries/LibWeb/Clipboard/ClipboardItem.h

@@ -46,7 +46,9 @@ public:
     Bindings::PresentationStyle presentation_style() const { return m_presentation_style; }
 
     Vector<String> const& types() const { return m_types; }
+
     Vector<Representation> const& representations() const { return m_representations; }
+    void append_representation(Representation);
 
     WebIDL::ExceptionOr<GC::Ref<WebIDL::Promise>> get_type(String const& type);