Allow Restore jobs to use node selector as per Backup

Currently the CouchbaseCluster.Spec.Backup.NodeSelector only applies to backup jobs, it would be good to allow restore jobs to also be configurable in this way.

A potential quick fix would be to reuse the same node selector for restore jobs - but does everyone want backup and restore to share node selectors (I imagine most would be ok with it)?

Should we provide a separate field for restore (CRD update) that can default to the existing backup one? We could provide a quick fix using the backup one for now and a longer term change to provide a separate CRD update that defaults to the existing one.