testing: Add scenarios that use a CA with two intermediate CA certificates

Mainly to test TKM's ability for handling multiple CAs and that the
received intermediate CA certificates are passed in the right order.
But also added a regular scenario where two intermediate CA certificates
are sent by one of the clients.

testing/tests/tkm/multi-level-ca/test.conf

@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# This configuration file provides information on the
+# guest instances used for this test
+
+# All guest instances that are required for this test
+#
+VIRTHOSTS="carol dave moon winnetou"
+
+# Corresponding block diagram
+#
+DIAGRAM="a-m-c-w-d.png"
+
+# Guest instances on which tcpdump is to be started
+#
+TCPDUMPHOSTS="carol dave"
+
+# Guest instances on which IPsec is started
+# Used for IPsec logging purposes
+#
+IPSECHOSTS="carol dave moon"
+
+# charon controlled by swanctl
+#
+SWANCTL=1