Click support and argument deprecation

Hab auch demos für alles mal gebaut :)

demos/argparse-example.py

+from netdb_client.api41 import APIEndpoint, APISession, dns
+
+from netdb_client import util
+
+parser = util.ArgumentParser()
+
+args = parser.parse_args()
+
+endpoint = APIEndpoint(**vars(args))
+api = APISession(endpoint)
+
+fqdn = dns.Fqdn.list(api, value_old='net.scc.kit.edu')
+
+print(fqdn)