provide information on sylva release in workload clusters

(credit for the idea goes to Sylvain Desbureaux)

It would be useful to make it possible, in a workload cluster, to have information on the Sylva release which deployed it. This can help users of the workload cluster that do not have access to the mgmt cluster.

The information could include:

• sylva-core version
• "sylva derivative" information (additional-info of sylva-units-status)

This information could be provided:

• as a configmap somewhere in the workload cluster
  • drawback: we would need to choose a namespace for it, and all wkld cluster users would not necessarily be able to see it without something giving them a Role able to read it
• to make this information available for all users, we can also provide this information as an annotations to the sylva-system namespace