Emit Notifications on concurrency group changes

Current situation

Not much information is reported to the workflow on concurrency group events (cancellation being the only one information produced)

Desired outcome

Notifications should be published on group events (running in a group, waiting in a group, completing in a group).

The notifications are regular Notification log events, with a group notification name. They must have a metadata.workflow_id entry and may have a metadata.job_id entry if the task is a Job.

Example notification

apiVersion: opentestfactory.org/v1alpha1
kind: Notification
metadata:
  creationTimestamp: '2025-04-03T09:50:11.387663+00:00'
  name: group notification
  namespace: default
  workflow_id: a1e4802b-43f0-4140-8fa5-4977bb2c8ed0
spec:
  logs:
  - (Completed in group "agroup default")