parser: fix scoped alias resolution

parser: fix scoped alias resolution

We tried to resolve aliases in some places where the cluster
configuration didn't get set. It's probably better to handle these cases
directly in the function at hand, instead of at every place where this
issues might arise.

This seemingly fixes the issues reported on pve-user and the forum:
  * https://forum.proxmox.com/threads/pve-8-pve-firewall-status-no-such-alias.130202/
  * https://forum.proxmox.com/threads/ipset-not-working-for-accepting-cluster-traffic.129599/

Signed-off-by: Leo Nunner <l.nunner@proxmox.com>