As a web-rca user I want to be able go thru Handover events and see which participants were part of handover.

Diagram: https://miro.com/app/board/uXjVIgsF1Ek=/?share_link_id=902195796589

Track handover history

• Record a history of the handovers. A timeline of who handed over the incident to who, and when.
• We will add table `event_participants` from `incident_participants`
• event_id, user_id, role
• Roles: before handover (incident_owner, incident_participant) and after handover (new_incident_owner, new_incident_participant)