testing: Add libipsec scenarios that exchange raw ESP packets

testing/tests/libipsec/net2net-cert-raw/posttest.dat

@@ -0,0 +1,5 @@
+moon::swanctl --terminate --ike gw-gw 2> /dev/null
+moon::systemctl stop strongswan
+sun::systemctl stop strongswan
+moon::iptables-restore < /etc/iptables.flush
+sun::iptables-restore < /etc/iptables.flush