add menuitemcheckbox and menuitemradio support to fast-menu-items

[MarcSkovMadsen]

I was trying to learn how the `fast-menu works.

Both from code and the component explorer I'm not able to select anything but the top menu-item.

I would have expected a the second and third fast-menu-item to be selected/ highlight when clicked just as the first one.

[chrisdholt]

Thanks for the note @MarcSkovMadsen - we're in process of adding the checkbox and radio behavior here. The current events would simply invoke the menu item. Let's use this issue to track the addition of the checkbox and radio events AND visual states.

@bheston for both the radio and checkbox menu instances, I think we'd want a "check" svg. One question I have is where we think that may go from a design standpoint. I'm not sure the start or end slot would be preferred. Do we have designs for menuitemcheckbox/menuitemradio instances? If so, we can finish this up quickly.

[MarcSkovMadsen]

The important thing here to note @chrisdholt and fix is that if I click the top menu-item it gets selected (fixed red color, border etc.). But that does not happen for other menu-items.