[path] Add global path command (#1077)

## Summary

Inspired by #1058

## How was it tested?

```bash
➜  devbox git:(landau/global-path) devbox global path
/Users/mike/.local/share/devbox/global/default
```

Author: mikeland73

internal/boxcli/global.go

@@ -25,6 +25,7 @@ func globalCmd() *cobra.Command {
 
 	addCommandAndHideConfigFlag(globalCmd, addCmd())
 	addCommandAndHideConfigFlag(globalCmd, installCmd())
+	addCommandAndHideConfigFlag(globalCmd, pathCmd())
 	addCommandAndHideConfigFlag(globalCmd, pullCmd())
 	addCommandAndHideConfigFlag(globalCmd, removeCmd())
 	addCommandAndHideConfigFlag(globalCmd, runCmd())

internal/boxcli/path.go

@@ -0,0 +1,32 @@
+// Copyright 2023 Jetpack Technologies Inc and contributors. All rights reserved.
+// Use of this source code is governed by the license in the LICENSE file.
+
+package boxcli
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+type pathCmdFlags struct {
+	config configFlags
+}
+
+func pathCmd() *cobra.Command {
+	flags := pathCmdFlags{}
+	cmd := &cobra.Command{
+		Use:     "path",
+		Short:   "Show path to [global] devbox config",
+		PreRunE: ensureNixInstalled,
+		Args:    cobra.ExactArgs(0),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			fmt.Println(flags.config.path)
+			return nil
+		},
+	}
+
+	flags.config.register(cmd)
+
+	return cmd
+}