feat(bootstrap): accept extra_addresses on network interfaces

roles/virtualization/templates/cloud-network-config.yml.j2

@@ -12,6 +12,9 @@ network:
 {% if has_static %}
       addresses:
         - "{{ iface.ip }}/{{ iface.prefix }}"
+{% for address in iface.extra_addresses | default([]) %}
+        - "{{ address }}"
+{% endfor %}
 {% if iface.gateway | default('') | string | length %}
       routes:
         - to: default