Update escalations when incident status is changed

Motivation

When a user updates the status of their incident, any active escalation for the incident should reflect that status change.

Scope

• Setting the status of an incident to Resolved (or Ignored) should delete the IncidentManagement::IssuableEscalations
• Setting the status of an incident from any closed status to Triggered should "reset" (delete & recreate) the IncidentManagement::IssuableEscalations for the incident.