Enable unset ptr test and add inactive value to floating ip status

Depends-On: https://review.opendev.org/c/openstack/designate/+/830549

Change-Id: Iba915b4701037b5ab33c57550c5f3dcddf01ccbc
diff --git a/designate_tempest_plugin/common/constants.py b/designate_tempest_plugin/common/constants.py
index 4f6c72b..96ed58b 100644
--- a/designate_tempest_plugin/common/constants.py
+++ b/designate_tempest_plugin/common/constants.py
@@ -18,6 +18,7 @@
 ERROR = 'ERROR'
 DELETED = 'DELETED'
 ACTIVE = 'ACTIVE'
+INACTIVE = 'INACTIVE'
 UP = 'UP'
 CREATE = 'CREATE'