[Techsupport] Add show route-map command to frr dumps in techsupport (sonic-net#3797)

What I did
Adding show route-map commamnd to frr dump in techsupport. This will provide detailed information about route-map across different daemons which is useful for debugging.

Example

ZEBRA:
route-map: TO_BGP_PEER_V4 Invoked: 0 Optimization: enabled Processed Change: false
 permit, sequence 100 Invoked 0
  Match clauses:
  Set clauses:
  Call clause:
    Call CHECK_IDF_ISOLATION
  Action:
    Exit routemap
BGP:
route-map: TO_BGP_PEER_V4 Invoked: 0 Optimization: enabled Processed Change: false
 permit, sequence 100 Invoked 0
  Match clauses:
  Set clauses:
  Call clause:
    Call CHECK_IDF_ISOLATION
  Action:
    Exit routemap
How I did it
Adding the command to list of commands dumped from frr in techsupport.

How to verify it
Running techsupport and verifying

Author: dgsudharsan

scripts/generate_dump

@@ -806,6 +806,7 @@ save_frr_info() {
     save_vtysh "show mpls table" "frr.mpls.table"
     save_vtysh "show mpls fec" "frr.mpls.fec"
     save_vtysh "show nexthop-group rib" "frr.nhg.rib"
+    save_vtysh "show route-map" "frr.route_map"
     save_vtysh "show thread cpu" "frr.thread_cpu"
     save_vtysh "show thread poll" "frr.thread_poll"
     save_vtysh "show debugging hashtable" "frr.debugging_hashtable"