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/reauth-mbb-virtual-ip/description.txt

@@ -1,8 +0,0 @@
-This scenario tests <b>make-before-break reauthentication</b> using overlapping
-IKE_SAs by setting the <i>make_before_break</i> strongswan.conf option for
-clients using an assigned virtual IP. The initiator <b>carol</b> reauthenticates
-the IKE_SA with host <b>moon</b> using <b>ikelifetime=10s</b>, but does not
-close the old IKE_SA before the replacement CHILD_SA using the same virtual IP
-is in place. A constant ping from <b>carol</b> to client <b>alice</b>
-hiding in the subnet behind <b>moon</b> tests if the CHILD_SA works during the
-whole procedure.