exit: store VLAN interface addresses in NetBox

… instead of generating them from prefixes. A NetBox script can be
used to create and configure all necessary data for a new VLAN.

Instead of VLAN roles “inside" and “outside” we now create separate
VRFs for inside VLANs to match the actual exit/firewall configuration.
The “outside” VRF is for all VLANs that are directly accessible from
the internet.

roles/exit/templates/radvd.conf.j2

@@ -1,6 +1,5 @@
-{# Note that there must be exactly one VLAN-aware bridge. #}
-{% set bridge = interfaces | selectattr('type') | selectattr('type.value', '==', 'bridge') | first %}
-{% set my_vlans = bridge.tagged_vlans | sort(attribute='vid') -%}
+{% set my_vlans = interfaces | selectattr('parent') | selectattr('parent.name', '==', 'bridge')
+    | selectattr('untagged_vlan') | map(attribute='untagged_vlan') -%}
 
 # Send IPv6 RAs from virtual router IP for each network. Also set DNS options.
 # Both exits announce the same gateway, so don’t revoke it if we go down.