library/DIAMETER_Emulation: implement 'raw' mode of operation

This patch implements a new mode of operation, which allows to
have direct communication between the emulation component and
the other component connected via the 'DIAMETER_UNIT' port.
This eliminates the need to have dedicated components for each
IMSI, what is not necessarily needed in some specific cases.

Change-Id: I52e22ac70cc85be5b0436b68c77356aabc4f05e1
Related: SYS#5602
diff --git a/mme/MME_Tests.ttcn b/mme/MME_Tests.ttcn
index 375a66a..3c35359 100644
--- a/mme/MME_Tests.ttcn
+++ b/mme/MME_Tests.ttcn
@@ -213,7 +213,8 @@
 friend function f_init_diameter(charstring id) runs on MTC_CT {
 	var DIAMETEROps ops := {
 		create_cb := refers(DIAMETER_Emulation.ExpectedCreateCallback),
-		unitdata_cb := refers(DiameterForwardUnitdataCallback)
+		unitdata_cb := refers(DiameterForwardUnitdataCallback),
+		raw := false /* handler mode (IMSI based routing) */
 	};
 	var DIAMETER_conn_parameters pars := {
 		remote_ip := mp_mme_ip,