start implementing the TC_paging() PCU test

Implement a basic paging test for the PCU, which is passing for paging
via TMSI (but only if osmo-pcu is started after the test is started).

Previously, this test code amounted to a debugging loop which
never terminated.

Change-Id: Id0384e0742ab91983615e4f1c883bb044c1c8b18
Related: OS#2404
diff --git a/library/L3_Templates.ttcn b/library/L3_Templates.ttcn
index e109fde..3918f3d 100644
--- a/library/L3_Templates.ttcn
+++ b/library/L3_Templates.ttcn
@@ -303,6 +303,22 @@
 	}
 }
 
+/* Template for receiving a Paging Request Type1 message with a given TMSI in the first mobile identity. */
+template MobileL3_CommonIE_Types.MobileIdentityLV tr_PAGING_REQ1_MI1_TMSI(octetstring tmsi) := {
+	lengthIndicator := 5,
+	mobileIdentityV := {
+		typeOfIdentity := '100'B,
+		oddEvenInd_identity := {
+			tmsi_ptmsi := {
+				oddevenIndicator := '0'B,
+				fillerDigit := '1111'B,
+				octets := tmsi
+			}
+		}
+	}
+
+}
+
 template PDU_ML3_NW_MS tr_PAGING_REQ2(template TMSIP_TMSI_V mi1 := ?,
 				      template TMSIP_TMSI_V mi2 := ?,
 				      template MobileIdentityTLV mi3 := *) := {