Allow configurable classes for menu items even if provided by a module

I wrote everything i knew in the queue of Menu Link Attributes module, which at least hasn’t stated a hard no against providing this.

Provide a way of adding attributes to module-provided links · Issue #45 · yannickoo/menu_link_attributes

The Link Attributes widget module said explicitly it won’t support this.

Definitely curious if there’s anything about this module (Menu Link Attributes) that makes this more possible or if this module more amenable to bolting it on.

Hold on, we have a core issue about changing titles of code-provided menu that might shed some light on this…

Allow override the menu link titles at core.menu.static_menu_link_overrides.yml
https://www.drupal.org/node/2916639

(Oh wanted to mention that the recommended workaround for link attributes is to disable the code-provided menu, and create a custom menu item, but that is deeply unsatisfying when trying to get everything into configuration, which is like the whole game for sustainable development and necessary for building distributions like Drutopia.)

Related: https://stackoverflow.com/questions/46114027/add-menu-class-in-drupal8