[sonic-utilities] Fix show vnet [neighbors | routes [all | tunnel]] crashed issue (#1263)

When query "NEIGH_TABLE*" or "VNET_ROUTE_TUNNEL_TABLE*" from APPDB,
it may contain a combination of table names with and without ":"

This PR shall skip handling the below entries in APP_DB:

127.0.0.1:6379> keys NEIGH_TABLE*

"NEIGH_TABLE_DEL_SET"
"NEIGH_TABLE_KEY_SET"

Author: CLUDev

show/main.py

@@ -2291,7 +2291,7 @@ def neighbors():
     appl_db.connect(appl_db.APPL_DB)
 
     # Fetching data from appl_db for neighbors
-    nbrs = appl_db.keys(appl_db.APPL_DB, "NEIGH_TABLE*")
+    nbrs = appl_db.keys(appl_db.APPL_DB, "NEIGH_TABLE:*")
     nbrs_data = {}
     for nbr in nbrs if nbrs else []:
         tbl, intf, ip = nbr.split(":", 2)
@@ -2331,7 +2331,7 @@ def all():
     header = ['vnet name', 'prefix', 'nexthop', 'interface']
 
     # Fetching data from appl_db for VNET ROUTES
-    vnet_rt_keys = appl_db.keys(appl_db.APPL_DB, "VNET_ROUTE_TABLE*")
+    vnet_rt_keys = appl_db.keys(appl_db.APPL_DB, "VNET_ROUTE_TABLE:*")
     vnet_rt_keys = natsorted(vnet_rt_keys) if vnet_rt_keys else []
 
     table = []
@@ -2350,7 +2350,7 @@ def all():
     header = ['vnet name', 'prefix', 'endpoint', 'mac address', 'vni']
 
     # Fetching data from appl_db for VNET TUNNEL ROUTES
-    vnet_rt_keys = appl_db.keys(appl_db.APPL_DB, "VNET_ROUTE_TUNNEL_TABLE*")
+    vnet_rt_keys = appl_db.keys(appl_db.APPL_DB, "VNET_ROUTE_TUNNEL_TABLE:*")
     vnet_rt_keys = natsorted(vnet_rt_keys) if vnet_rt_keys else []
 
     table = []
@@ -2374,7 +2374,7 @@ def tunnel():
     header = ['vnet name', 'prefix', 'endpoint', 'mac address', 'vni']
 
     # Fetching data from appl_db for VNET TUNNEL ROUTES
-    vnet_rt_keys = appl_db.keys(appl_db.APPL_DB, "VNET_ROUTE_TUNNEL_TABLE*")
+    vnet_rt_keys = appl_db.keys(appl_db.APPL_DB, "VNET_ROUTE_TUNNEL_TABLE:*")
     vnet_rt_keys = natsorted(vnet_rt_keys) if vnet_rt_keys else []
 
     table = []