Add OVA script support

1. Ensure that system_template and script are not nullable in the DB.
2. Ensure that the CLI and API enforce the above and clean up CLI
arguments for profile add.
3. Ensure that, before uploading OVAs, a 'default_ova' provisioning
script is present.
4. Use the 'default_ova' script for new OVA uploads.
5. Ensure that OVA details are properly added to the vm_data dict in the
provisioner vmbuilder.

api-daemon/pvcapid/vmbuilder.py

@@ -277,6 +277,8 @@ def create_vm(
             vm_data["script"] = db_row.get("script")
         else:
             vm_data["script"] = None
+
+        if profile_data.get("profile_type") == "ova":
             query = "SELECT * FROM ova WHERE id = %s"
             args = (profile_data["ova"],)
             db_cur.execute(query, args)
@@ -285,6 +287,7 @@ def create_vm(
             query = "SELECT * FROM ova_volume WHERE ova = %s"
             args = (profile_data["ova"],)
             db_cur.execute(query, args)
+            # Replace the existing volumes list with our OVA volume list
             vm_data["volumes"] = db_cur.fetchall()
 
     retcode, stdout, stderr = pvc_common.run_os_command("uname -m")