Enable loadbalance plugin for submariner-lighthouse-corends

[t0lya]

What would you like to be added:
Add loadbalance plugin to submariner-lighthouse-coredns Corefile. See https://github.com/submariner-io/submariner-operator/pull/3309/files

Why is this needed:

We would like to randomize A records for headless services to better distribute load across the services' target pods. This is how Kubernetes' built-in CoreDNS behaves, as loadbalance plugin is added default there https://kubernetes.io/docs/tasks/administer-cluster/dns-custom-nameservers/#coredns-configmap-options. We would like to enable same behavior for submariner-lighthouse-coredns to keep DNS resolution behavior consistent across cluster.local and clusterset.local zones.