testing: Add ikev2/per-cpu-sas-encap scenario

Basically the same as the one without UDP encapsulation, but here the
outbound SAs use random source ports.

testing/tests/ikev2/per-cpu-sas-encap/hosts/moon/etc/strongswan.conf

@@ -0,0 +1,15 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+swanctl {
+  load = pem pkcs1 revocation constraints pubkey openssl random
+}
+
+charon-systemd {
+  load = random nonce openssl pem pkcs1 revocation curl kernel-netlink socket-default updown vici
+
+  syslog {
+    daemon {
+      knl = 2
+    }
+  }
+}