MSC_Tests: Support wildcarded endpoints

At the moment the testsuite is unable to detect when the call agent
performs a CRCX request with a wildcarded endpoint.

- Set a default endpoint name in cpars in case the MSC does
  a CRCX request with wildcarded endpoint name.

- Detect if the MSC supplied a wildcarded endpoint name. Do
  not overwrite the default setting in cpars then.

- Attach the endpoint name as Z: parameter in the response so
  that the MSC knows which endpoint to use. (Unconditional,
  does not harm on non wildcarded requests)

Change-Id: I0efeae0f8a6e98deb843e79648f84a262f1d98f8
Related: OS#2710
diff --git a/msc/MSC_Tests.ttcn b/msc/MSC_Tests.ttcn
index 159538c..e7ee9e7 100644
--- a/msc/MSC_Tests.ttcn
+++ b/msc/MSC_Tests.ttcn
@@ -1604,6 +1604,10 @@
 	cpars.mgcp_connection_id_bss := '10004'H;
 	cpars.mgcp_connection_id_mss := '10005'H;
 
+	/* Note: This is an optional parameter. When the call-agent (MSC) does
+	 * supply a full endpoint name this setting will be overwritten. */
+	cpars.mgcp_ep := "rtpbridge/1@mgw";
+
 	f_perform_lu();
 	f_mt_call(cpars);
 }