gprs_ns2_vty: add optional argument signalling and data weights to `nsvc udp`

A static configured UDP NSVC can have signalling and data weights

Related: SYS#5354
Change-Id: Id363937c64e786c55e3136401ebdb44052415e0f
diff --git a/tests/gb/gprs_ns2_vty.vty b/tests/gb/gprs_ns2_vty.vty
index a748f13..a969881 100644
--- a/tests/gb/gprs_ns2_vty.vty
+++ b/tests/gb/gprs_ns2_vty.vty
@@ -32,3 +32,32 @@
 UDP bind: 127.0.0.14:42999 DSCP: 0
   IP-SNS signalling weight: 1 data weight: 1
   0 NS-VC: 
+OsmoNSdummy# configure terminal
+OsmoNSdummy(config)# ns
+OsmoNSdummy(config-ns)# nse 1234
+OsmoNSdummy(config-ns-nse)# nsvc udp abc 127.0.0.15 9496
+OsmoNSdummy(config-ns-nse)# end
+OsmoNSdummy# show ns
+NSEI 01234: UDP, DEAD
+ NSVCI none: RECOVERING PERSIST data_weight=1 sig_weight=1 udp)[127.0.0.14]:42999<>[127.0.0.15]:9496
+UDP bind: 127.0.0.14:42999 DSCP: 0
+  IP-SNS signalling weight: 1 data weight: 1
+  1 NS-VC: 
+    NSVCI 00000: udp)[127.0.0.14]:42999<>[127.0.0.15]:9496
+OsmoNSdummy# configure terminal
+OsmoNSdummy(config)# ns
+OsmoNSdummy(config-ns)# nse 1234
+OsmoNSdummy(config-ns-nse)# nsvc udp abc 127.0.0.16 9496 signalling-weight 0 data-weight 9
+OsmoNSdummy(config-ns-nse)# nsvc udp abc 127.0.0.17 9496 signalling-weight 0 data-weight 0
+OsmoNSdummy(config-ns-nse)# end
+OsmoNSdummy# show ns
+NSEI 01234: UDP, DEAD
+ NSVCI none: RECOVERING PERSIST data_weight=0 sig_weight=0 udp)[127.0.0.14]:42999<>[127.0.0.17]:9496
+ NSVCI none: RECOVERING PERSIST data_weight=9 sig_weight=0 udp)[127.0.0.14]:42999<>[127.0.0.16]:9496
+ NSVCI none: RECOVERING PERSIST data_weight=1 sig_weight=1 udp)[127.0.0.14]:42999<>[127.0.0.15]:9496
+UDP bind: 127.0.0.14:42999 DSCP: 0
+  IP-SNS signalling weight: 1 data weight: 1
+  3 NS-VC: 
+    NSVCI 00000: udp)[127.0.0.14]:42999<>[127.0.0.17]:9496
+    NSVCI 00000: udp)[127.0.0.14]:42999<>[127.0.0.16]:9496
+    NSVCI 00000: udp)[127.0.0.14]:42999<>[127.0.0.15]:9496