fix(schema): add unique identifiers for MlagDomain VLAN relationships

Add identifier and direction: outbound for peer_vlan and ibgp_vlan
to avoid bidirectional relationship conflicts.

Ref: #41

schemas/mlag.yml

@@ -52,11 +52,15 @@ nodes:
         description: MLAG peer devices
       - name: peer_vlan
         peer: InfraVLAN
+        identifier: mlag_domain_peer_vlan
         cardinality: one
+        direction: outbound
         description: VLAN for MLAG peer-link control traffic
       - name: ibgp_vlan
         peer: InfraVLAN
+        identifier: mlag_domain_ibgp_vlan
         cardinality: one
+        direction: outbound
         optional: true
         description: VLAN for iBGP peering between MLAG peers