click on Notification entry navigates to the relevant view (e.g. details of the changed entity)

[sleidig]

The basic functionality is already implemented in PR #2738.
To make this less error-prone, we should maybe dynamically generate the actionUrl in the NotificationEvent class based on the notificationType , e.g. for entity_change the link can be generated by looking up the current route for that entityType instead of hard-coding the link into each NotificationEvent document (any maybe leading into nothing if the admin changes the route for that entity type).