Generate and manage certificates for kube-scheduler and kube-controller-manager

[manuelbuil]

Is your feature request related to a problem? Please describe.

We are currently not generating the self-signed certificates of kube-scheduler and kube-controller-manager which makes it impossible to rotate them either by using the CLI or by rebooting the nodes

Describe the solution you'd like

K3s having control over kube-scheduler and kube-controller-manager certificates

Describe alternatives you've considered

Additional context

[brandond]

1. We need to generate additional certs+keys in the same paths as the components use when generating self-signed certs:
   /var/lib/rancher/k3s/server/tls/{component}/{component}.{crt,key}
2. We will need to pass --cert-dir in the component args:
   --cert-dir=/var/lib/rancher/k3s/server/tls/{component}
3. The cert will need to be signed by the K3s ServerCA and have the full ServerCA chain in it, as Rancher is using the cert as the CA bundle because it expects the cert to be self-signed.