enable rabbitmq management and add admin permissions

- allow database creation for gnuviechadmin user in local deployments to
  allow test runs
- set administrator tag for gnuviechadmin user in rabbitmq
- add all permissions on gnuviechadmin vhost to gnuviechadmin user
- enable rabbitmq management plugin

roots/rabbitmq-server/init.sls

@@ -9,3 +9,9 @@ rabbitmq-server:
 guest:
   rabbitmq_user:
     - absent
+
+rabbitmq_management:
+  rabbitmq_plugin:
+    - enabled
+    - watch_in:
+      - service: rabbitmq-server