[Alerting UI] Ability for alert type to define the context specific name for Recovered action group

[YulNaumenko]

Describe the feature:
Recovered action group should support context specific names in UI.

Describe a specific use case for the feature:
Currently the Recovered action group appears in the Action form dropdown as "Recovered", but this name is very generic a could have a different meanings depends on the context of the alert type. For example for geo-alert 'recovered' doesn't make any word sense for the user.

[elasticmachine]

Pinging @elastic/kibana-alerting-services (Team:Alerting Services)

[pmuellr]

This makes sense, I'm wondering where else we need this beyond just the UI.

It seems like this needs to be server-side somewhere as well, since we now have the action group in the mustache variables we render action parameters with. I'm wondering if we want to expose both the "standard" action group 'recovered' (or whatever 'resolved' becomes) AND the "renamed" version. Which do we put in the event log? I doubt we want both, but not sure.

It feels like mainly a UI thing, but not completely.