Add empty talkreq command to dcli

eth/p2p/discoveryv5/dcli.nim

@@ -9,6 +9,7 @@ type
     noCommand
     ping
     findnode
+    talkreq
 
   DiscoveryConf* = object
     logLevel* {.
@@ -71,6 +72,11 @@ type
         argument
         desc: "ENR URI of the node to send a findNode message"
         name: "node" .}: Node
+    of talkreq:
+      talkreqTarget* {.
+        argument
+        desc: "ENR URI of the node to send a talkreq message"
+        name: "node" .}: Node
 
 proc parseCmdArg*(T: type enr.Record, p: TaintedString): T =
   if not fromURI(result, p):
@@ -173,6 +179,12 @@ proc run(config: DiscoveryConf) =
         echo $node.record & " - " & shortLog(node)
     else:
       echo "No Nodes message returned"
+  of talkreq:
+    let talkresp = waitFor d.talkreq(config.talkreqTarget, @[], @[])
+    if talkresp.isOk():
+      echo talkresp[]
+    else:
+      echo "No Talk Response message returned"
   of noCommand:
     d.start()
     runForever()