GlMenu: First iteration of a Menu
In order to reduce the complexity of our existing GlDropdown implementation, we want to implement a semantically correct GlMenu component.
Menu: A menu dropdown is a button that toggles a panel containing a list of actions or functions, similar to the way a menu works in an operating system or native application. This type of dropdown uses role="menu" which puts a screen reader into application mode and uses different keyboarding than regular browse and read mode. For this reason, a menu dropdown isn’t suitable for navigation, and should only be used for JavaScript initiated actions.