Claims with cluster label should not be reconciled when cluster cannot be retrieved

[tylerschultz]

When using Velero to do a backup/restore, we see that claims are getting reconciled when the paused cluster has yet to be restored. We see that the cluster is always restored last, due to the dependency tree.

Our use case is Velero specific, but we think this is a more general bug too. If a claim is linked to a cluster and it can't be retrieved, we think it should skip reconciliation until the cluster can be evaluated.