[Overlay] Tab catching elements can disturb UI deliver

[Westbrook]

Expected Behaviour

Opening an overlay should allow triggering content to maintain layout.

Actual Behaviour

In certain situations the the shift + tab manager allows for styling to be triggered on sibling/parent elements. Thanks @hunterloftis for catching this!

Reproduce Scenario (including but not limited to)

https://opensource.adobe.com/spectrum-web-components/storybook/index.html?path=/story/top-nav--modes

Steps to Reproduce

Open/close the action menu at the far right of the above story.

Closed

Opened