feat: enable nomad to manage sessions/services (#222)

- this is required to start patroni

Reviewed-on: https://git.query.consul/unkinben/puppet-prod/pulls/222

hieradata/roles/infra/nomad/agent.yaml

@@ -64,3 +64,9 @@ profiles::consul::client::node_rules:
   - resource: service_prefix
     segment: ''
     disposition: write
+  - resource: key_prefix
+    segment: "nomad"
+    disposition: write
+  - resource: session_prefix
+    segment: ""
+    disposition: write