MenuItem: support passthrough attributes

[torstenwerner]

Describe the defect

Sample xhtml code with xmlns:pt="http://xmlns.jcp.org/jsf/passthrough":

<p:menuitem value="Neuer Ordner" update="folderTree" action="#{folderTreeView.addNewNode}"
    oncomplete="openInplace(args)" icon="fa fa-plus"
    onkeydown="test()" pt:onkeydown="test2()" pt:data-test3="test4"/>

The rendered DOM has neither a onkeydown event handler defined nor a custom attribute data-test3.

<li class="ui-menuitem ui-widget ui-corner-all" role="none"><a tabindex="-1" role="menuitem"
                                                           class="ui-menuitem-link ui-corner-all" href="#"
                                                           onclick="PrimeFaces.ab({s:&quot;folder-tree:treeform:j_idt17&quot;,f:&quot;folder-tree:treeform&quot;,u:&quot;folder-tree:treeform:folderTree&quot;,onco:function(xhr,status,args,data){openInplace(args);}});return false;"><span
    class="ui-menuitem-icon ui-icon fa fa-plus" aria-hidden="true"></span><span class="ui-menuitem-text">Neuer Ordner</span></a>
</li>

Reproducer

Add the menuitem sample to any application and check the rendered DOM.

Environment:

• PF Version: 10.0.0
• JSF + version: Mojarra 2.3.16
• Affected browsers: ALL

To Reproduce
Steps to reproduce the behavior:

1. Add the menuitem sample to any application.
2. Check the rendered DOM.

Expected behavior
I expected to be able to define custom event handlers and custom attributes as it is possible for other components.

[tandraschko]

new feature as not implemented before

[tandraschko]

a PR would be great!

[melloware]

MenuIten is a UICommand and not a UIComponent so I don't think this feature can be implemented. I am not sure it's even worth trying to change MenuIten for this. Going to close for now.

[melloware]

Sorry thanks to @Rapster i realized this can be done and quite easily.