testing: Migrated ikev2 scenarios to swanctl

testing/tests/ikev2/nat-rw/description.txt

@@ -1,5 +1,7 @@
 The roadwarriors <b>alice</b> and <b>venus</b> sitting behind the NAT router <b>moon</b> set up
 tunnels to gateway <b>sun</b>. UDP encapsulation is used to traverse the NAT router.
+Authentication is based on X.509 certificates.
+<p/>
 <b>leftfirewall=yes</b> automatically inserts iptables-based firewall rules that let pass
 the tunneled traffic. In order to test the tunnel, the NAT-ed hosts <b>alice</b> and <b>venus</b>
 ping the client <b>bob</b> behind the gateway <b>sun</b>.