Kibana version: master

Summary

There's a few enhancements we can add to make the popover consistent with the other Observability apps.

• The title of the popover for alerts displays a generic "main panel" title. It should say "Alerts" like the button link that invoked the popover.
• The padding inside the popover looks off, compared to the default popover.

Example from APM

APM will change the active alerts link to be consistent