Nested Menus with <nolink>

This is the first pass on adding support for nested menus without controls, there are several use cases that need to be discussed before this is approved.

Use cases we need to test for:

• Menu items with nested menus using default for label
• Nested menu with using elements other than span
• Nested menu with button menus in same list

jldust → credited pixelwhip → .

I've updated the merge request to handle various types of nested menus including those that are expanded and have a link as the root menu item. The escape and left keys now only escapes to the closest button in case of nested menus. This behavior more closely matches https://www.w3.org/WAI/ARIA/apg/patterns/menubar/examples/menubar-naviga...

jldust → credited philip_stier → .

Thanks for all the feedback and edits, this has been merged in and will be included in the next tagged release.

Automatically closed - issue fixed for 2 weeks with no activity.