testing: Add scenarios that use XFRM interfaces

The network namespace scenario requires a kernel patch in 4.19 and 4.20
kernels (the fix is included in 5.0 kernels).

testing/tests/route-based/rw-shared-xfrmi/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="alice moon carol winnetou dave"
+
+# Corresponding block diagram
+#
+DIAGRAM="a-m-c-w-d.png"
+
+# Guest instances on which tcpdump is to be started
+#
+TCPDUMPHOSTS="moon"
+
+# Guest instances on which IPsec is started
+# Used for IPsec logging purposes
+#
+IPSECHOSTS="moon carol dave"
+
+# charon controlled by swanctl
+#
+SWANCTL=1