commands: use parseChanIDs method

In this commit we use the `parseChanIDs` method introduced in a
previous commit to process the `outgoing_chan_id` flag for
`queryroutes`.

Author: Abdulkbk

cmd/commands/cmd_payments.go

@@ -1286,16 +1286,13 @@ func queryRoutes(ctx *cli.Context) error {
 
 	outgoingChanIds := ctx.StringSlice("outgoing_chan_id")
 	if len(outgoingChanIds) != 0 {
-		req.OutgoingChanIds = make([]uint64, len(outgoingChanIds))
-		for i, chanID := range outgoingChanIds {
-			id, err := strconv.ParseUint(chanID, 10, 64)
-			if err != nil {
-				return fmt.Errorf("invalid outgoing_chan_id "+
-					"argument: %w", err)
-			}
-
-			req.OutgoingChanIds[i] = id
+		chanIDs, err := parseChanIDs(outgoingChanIds)
+		if err != nil {
+			return fmt.Errorf("unable to decode "+
+				"outgoing_chan_id: %w", err)
 		}
+
+		req.OutgoingChanIds = chanIDs
 	}
 
 	if ctx.IsSet("route_hints") {