Add NS server entries to the model and deploy pdns on backend

Related-PROD: https://mirantis.jira.com/browse/PROD-12631
Related-PROD: https://mirantis.jira.com/browse/PROD-14396

Depends-On: I214d8db39365648b5ef9348b52edd839327ca197
Change-Id: I5a6eaa31bb0b9f4277dbec5eb8c7464546079b9f
5 files changed