gbproxy: Add test cases for STATUS handling

We expect the uplink BSSGP status to be routed based in the
inner/contained downlink PDU - and vice-versa.

Change-Id: If2ddd158346a3da340f1c673354196f3872c4f67
Related: OS#4951
diff --git a/library/Osmocom_Gb_Types.ttcn b/library/Osmocom_Gb_Types.ttcn
index 589108f..f97b9b0 100644
--- a/library/Osmocom_Gb_Types.ttcn
+++ b/library/Osmocom_Gb_Types.ttcn
@@ -1427,7 +1427,7 @@
 	}
 
 	/* 10.4.14 */
-	template PDU_BSSGP ts_BSSGP_STATUS(template BssgpBvci bvci, template BssgpCause cause,
+	template PDU_BSSGP ts_BSSGP_STATUS(template (omit) BssgpBvci bvci, template BssgpCause cause,
 					   PDU_BSSGP pdu) := {
 		pDU_BSSGP_STATUS := {
 			bssgpPduType := '41'O,
@@ -1443,12 +1443,12 @@
 			}
 		}
 	}
-	template PDU_BSSGP tr_BSSGP_STATUS(template BVCI bvci := ?, template BssgpCause cause := ?,
+	template PDU_BSSGP tr_BSSGP_STATUS(template BssgpBvci bvci := ?, template BssgpCause cause := ?,
 					   template octetstring pdu := ?) := {
 		pDU_BSSGP_STATUS := {
 			bssgpPduType := '41'O,
 			cause := t_BSSGP_CAUSE(cause),
-			bVCI := bvci,
+			bVCI := t_BSSGP_BVCI(bvci),
 			pDU_in_Error := {
 				iEI := '15'O,
 				ext := '1'B,