testing: Add tkm xfrmproxy-expire test

This test asserts that the handling of XFRM expire messages from the
kernel are handled correctly by the xfrm-proxy and the Esa Event Service
(EES) in charon-tkm.

testing/tests/tkm/xfrmproxy-expire/hosts/moon/etc/strongswan.conf

@@ -0,0 +1,8 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+charon-tkm {
+  dh_mapping {
+    15 = 1
+    16 = 2
+  }
+}

testing/tests/tkm/xfrmproxy-expire/hosts/moon/etc/tkm/tkm.conf

@@ -0,0 +1,21 @@
+<tkmconfig>
+    <local_identity id="1">
+        <identity>moon.strongswan.org</identity>
+        <certificate>moonCert.pem</certificate>
+    </local_identity>
+    <policy id="1">
+        <mode>transport</mode>
+        <local>
+            <identity_id>1</identity_id>
+            <ip>192.168.0.1</ip>
+        </local>
+        <remote>
+            <identity>sun.strongswan.org</identity>
+            <ip>192.168.0.2</ip>
+        </remote>
+        <lifetime>
+            <soft>2</soft>
+            <hard>60</hard>
+        </lifetime>
+    </policy>
+</tkmconfig>