GitLab

* Implement preset xml and the menuHelper class to load them.

* Export a menu (menutype) as a preset xml

* Import/load a preset xml into a database driven menu (menutype)

* Menu Tree and Node classes implemented for menu module menu item hierarchy.

* Update menu module to use new Menu Tree and Node class. Move the HTML rendering to layout files to facilitate template overrides.

* Remove unused files.

* CodeStyle fixes

* Include exception message string in error message.

* Add filter by Tag to mod_article_category (#16945)

* add filteroption to select tag to filter

* all php logic to get selected filter option

* add nice lines to separate fitler by tag from the rest.

* fix code style

* conditional load tags. Only load when filter is used

* File mode fixed