Component to display relative dates

Is your feature request related to a problem? Please describe.

Presenting relative dates should be displayed in a consistent way, but there are enough details to consider to package them as reusable component.

Describe the solution you'd like

• Use Intl.RelatieTimeFormat() as the foundation.
• Wrap the date in a <time> tag for better semantics.
• Show the full, precise timestamp on hover.
• At least allow presenting "short" format dates, possibly long format if we need it.

Both Stormbox and Accounts settings need to display relative dates.

Describe alternatives you've considered

• Considered one-off implementation in accounts, but this is expected to a common pattern we'll want to re-use.

Additional context

• This came up while building Current Signins

Start in the shared components area of this Vue services-ui repository and review the Current Signins context linked in the issue. Build the reusable component around Intl.RelativeTimeFormat, with time semantics, hover timestamps, and short or long display formats. Done means Stormbox and Accounts can use the same component for consistent relative dates.