Use the DNSValidator of Netbox instead of HostnameValidator to allow wildcard entries

[a-belhadj]

Netbox validates the field dns_name with the following validator and allows wildcard entries like *.apps.mycluster.com

Netbox validator: https://github.com/netbox-community/netbox/blob/08ae1391618dad69866717681e79a56ad9414f80/netbox/ipam/validators.py#L31