Implement kubevirt cluster provider

The CLI requires a kubevirt provider to deploy clusters with the KubeVirt infrastructure provider for Cluster API.

Requirements

ocne cluster start --provider kubevirt uses Cluster API to deploy a cluster using KubeVirt
The target management cluster needs to have all relevant Cluster API controllers installed
The target management cluster needs to have the kubeconfig for the target deployment cluster available as a Secret
It must be possible to deploy using an ephemeral cluster
It must be possible to pivot the cluster and make it self-managed.
It must be possible to delete the cluster using an ephemeral cluster
The kubeconfig for the new cluster must be written to a reasonable place (read: ~/.kube/...)

It would be good to refactor the driver for OCI, as much of the code will be identical. The only real change will be what controllers to install and what default cluster should be installed: https://github.com/oracle-cne/ocne/blob/main/pkg/cluster/driver/capi/capi.go