testing: Reorganizing IKEv1 and IKEv2 examples

For documentation purposes the new folders ikev1-algs, ikev2-algs,
ikev1-multi-ca and ikev2-multi-ca have been created. Most of the
test cases have now been converted to the vici interface. The
remaining legacy stroke scenarios yet to be converted have been put
into the ikev2-stroke-bye folder.

For documentation purposes some legacy stroke scenarios will be kept
in the ikev1-stroke, ikev2-stroke and ipv6-stroke folders.

testing/tests/ikev2-stroke/host2host-cert/description.txt

@@ -0,0 +1,6 @@
+A connection between the hosts <b>moon</b> and <b>sun</b> is successfully set up.
+The authentication is based on X.509 certificates.
+<p/>
+Upon the successful establishment of the IPsec tunnel, <b>leftfirewall=yes</b>
+automatically inserts iptables-based firewall rules that let pass the tunneled traffic.
+In order to test the host-to-host tunnel <b>moon</b> pings <b>sun</b>.