CI: adapt packet-ci role to act as a molecule provisioner

To work with molecule, we need to use the name provided by molecule_yml
in inventory.

Inject the name in the VirtualMachineInstance (with a default to handle
non-molecule scenario) and get it back as part of inventory).

Account for no ansible groups

tests/cloud_playbooks/create-packet.yml

@@ -1,8 +1,11 @@
 ---
-
 - name: Provision Packet VMs
   hosts: localhost
   gather_facts: false
   become: true
-  roles:
-    - { role: packet-ci, vm_cleanup: false }
+  tasks:
+  - name: Create Kubevirt VMs
+    import_role:
+      name: packet-ci
+  - name: Update inventory for Molecule
+    meta: refresh_inventory