message: Monitoring: Add alert counts by severity to silence details page
  To match the silence lists page
diff: @@ -726,7 +726,9 @@ const SilencesDetailsPage = withFallback(
  <dt>Comments</dt>
  <dd>{comment || '-'}</dd>
  <dt>Firing Alerts</dt>
  - <dd>{alertsLoaded ? firingAlerts.length : <LoadingInline />}</dd>
  + <dd>
  + {alertsLoaded ? <SeverityCounts alerts={firingAlerts} /> : <LoadingInline />}
  + </dd>
  </dl>
  </div>
  </div>
  