testing: Migrate MOBIKE tests to vici

Note that the mobike-nat test has been removed as it basically did the same
as the mobike-virtual-ip-nat test.  Instead, the mobike-nat-mapping scenario
is added, which simulates a NAT router restart.

testing/tests/ikev2/mobike/hosts/sun/etc/strongswan.conf

@@ -0,0 +1,9 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+swanctl {
+  load = pem pkcs1 x509 revocation constraints pubkey openssl random
+}
+
+charon-systemd {
+  load = random nonce sha1 sha2 aes hmac pem pkcs1 x509 revocation constraints pubkey curve25519 gmp curl kernel-netlink socket-default resolve updown vici
+}