Setting to RTC - thanks for testing

This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/4517.

Mootools still loaded here

@infograf768 yes right, because it required by the modal script that used for select the article (example),
and JHtml::_('behavior.formvalidation'); still call mootools, this part hope will be fixed by related pull #4475

maybe I made a bad description,
this pull remove mootools usage in the menu editing template, but some fields that on this page still can load mootools

@infograf768 @Fedik Also the toolbar buttons have hard coded call to mootools #4475 takes care of that but needs some fixes on unit tests (the old behavior.core was injecting mt, the new is not…). As it is right now I realize that is quite hard to review and test it, so I will break it in more parts so it will be easier to reviewed and tested 😃

Shall we then merge this one as it solves the validation ?

@infograf768 Hathor seems to have overrides for all these views https://github.com/joomla/joomla-cms/blob/staging/administrator/templates/hathor/html/com_menus/item/edit.php#L48-L76

Shall we change that as well?