Add routes/custom-host permission for OpenShift Route with custom domain

[AryanP123]

Fixes #2247

[AryanP123]

Tested with openshift cluster:

kubectl apply -f clusterrole.yaml

kubectl apply -f role.yaml -n skupper

kubectl apply -f {reproduce site yaml file provided in issue} -n "$SKUPPER_NS"
sleep 5
kubectl get routeraccesses.skupper.io -n "$SKUPPER_NS"
kubectl get securedaccesses.skupper.io -n "$SKUPPER_NS"

NAME             STATUS   MESSAGE
skupper-router   Ready    OK
NAME                   STATUS   MESSAGE
skupper-grant-server   Ready    OK
skupper-router         Ready    OK