Digitalocean public private ip (#27269)

* When using private networking the ip_address key contains the private ip.
Add the following info to module output when available:
  - private_ipv4_address
  - public_ipv4_address
  - private_ipv6_address
  - public_ipv6_address

lib/ansible/modules/cloud/digital_ocean/digital_ocean.py

@@ -232,6 +232,12 @@ class Droplet(JsonfyMixIn):
         if attrs:
             for k, v in attrs.items():
                 setattr(self, k, v)
+            networks = attrs.get('networks', {})
+            for network in networks.get('v6', []):
+                if network['type'] == 'public':
+                    setattr(self, 'public_ipv6_address', network['ip_address'])
+                else:
+                    setattr(self, 'private_ipv6_address', network['ip_address'])
         else:
             json = self.manager.show_droplet(self.id)
             if json['ip_address']: