[ActionButton, ActionGroup] examples should be accessible

[astearns]

Description

The Storybook Action button (and Action group) examples do not have an accessible name in the icon-only versions. The versions that have a name in the markup have a duplicate aria-label attribute, but the ones that do not have a name in the markup are missing that attribute.

Link to documentation

https://opensource.adobe.com/spectrum-css/preview/index.html?path=/story/components-action-button--default

Additional context

I assume the stories/template should be set up more like the spectrum-Button examples, which add an aria-label attribute for the versions with no markup name, and do not add the attribute for the versions with the name in the markup. I’d be happy to submit a PR with this documentation fix if this is correct.