Move the Kubernets provider to a different repository

[javiertoledo]

The current implementation of the K8s provider is not currently fully implemented and we have no immediate plans to finish it, but is in the repository requiring code updates as we make changes in other providers, so it's a bit in our way at the moment.

We think that we should move it out of the main repository to keep focusing on the cloud implementations. We could eventually revive it in the future if it's used and it makes sense to maintain it.

If you take this ticket, make sure to also update the CLI and the documentation to remove the references to this provider.