tabs: "quiet" lack of border is applied to vertical, compact tabs

[hunterloftis]

Description

Re: conversation w/ @pfulton and PJ, vertical compact should have a border, but currently doesn't:

https://opensource.adobe.com/spectrum-css/tabs.html#compactverticaltabs

Screenshots

I'm adding this issue to track, so I can override it temporarily in Spectrum Web Components & then delete the override once this is 👍