TUN-3809: Allow routes ip show to output as JSON or YAML

It also fixes the marshelling of CIDR into JSON since otherwise
it would show garbled characters as the mask.

cmd/cloudflared/tunnel/teamnet_subcommands.go

@@ -41,7 +41,7 @@ func buildRouteIPSubcommand() *cli.Command {
 				Usage:       "Show the routing table",
 				UsageText:   "cloudflared tunnel [--config FILEPATH] route ip show [flags]",
 				Description: `Shows your organization's private route table. You can use flags to filter the results.`,
-				Flags:       teamnet.FilterFlags,
+				Flags:       showRoutesFlags(),
 			},
 			{
 				Name:        "delete",
@@ -62,6 +62,13 @@ func buildRouteIPSubcommand() *cli.Command {
 	}
 }
 
+func showRoutesFlags() []cli.Flag {
+	flags := make([]cli.Flag, 0)
+	flags = append(flags, teamnet.FilterFlags...)
+	flags = append(flags, outputFormatFlag)
+	return flags
+}
+
 func showRoutesCommand(c *cli.Context) error {
 	sc, err := newSubcommandContext(c)
 	if err != nil {