[ic-popover-menu]: Introduce a variant of `ic-menu-item` that has the role `menuitemradio`

## Summary

- Introduce a variant of `ic-menu-item` that has the role [`menuitemradio`](https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Roles/menuitemradio_role)
- Introduce a variant of `ic-menu-group` that acts as a radio group to allow the radio menuitems to work together
- Introduce a variant of `ic-popover-menu` that acts as a radio group to allow the radio menuitems to work together

## 💬 Description
Currently, we have a variant of `ic-menu-item` that has the role `menuitemcheckbox` (`variant="toggle"`). It would be nice to have a variant of `ic-menu-item` that has the role `menuitemradio`.

## 💰 User value
This would allow users to create a menu where menuitems are mutually exclusive to each other

[See CodePen example of menubar](https://www.w3.org/WAI/ARIA/apg/patterns/menubar/examples/menubar-editor/)(role="menuitemradio" can be seen with the "Text align" menu items)

## ✏ Designs
In terms of design, it may be nice for the radio menu items follow the same design as toggle menu items

Start by reading the existing `ic-menu-item` toggle variant and the related `ic-menu-group` and `ic-popover-menu` implementations. Compare their behavior with the linked `menuitemradio` guidance and CodePen example; done means the requested radio variants support mutually exclusive menu items and follow the existing toggle-item design.

Written by the indexing model from the issue text.