In k3s today the kubernetes API and the /v1-k3s API are combined into
one http server.  In rke2 we are running unmodified, non-embedded Kubernetes
and as such it is preferred to run k8s and the /v1-k3s API on different
ports.  The /v1-k3s API port is called the SupervisorPort in the code.

To support this separation of ports a new shim was added on the client in
then pkg/agent/proxy package that will launch two load balancers instead
of just one load balancer.  One load balancer for 6443 and the other
for 9345 (which is the supervisor port).