feat(dropbox): add root_namespace_id to access teams folder (#5929)

* feat(dropbox): add root_namespace_id to access teams folder

* fix(dropbox): get_current_account API request

* feat(dropbox): extract root_namespace_id properly

* style: format code

drivers/dropbox/meta.go

@@ -17,7 +17,8 @@ type Addition struct {
 	ClientID      string `json:"client_id" required:"false" help:"Keep it empty if you don't have one"`
 	ClientSecret  string `json:"client_secret" required:"false" help:"Keep it empty if you don't have one"`
 
-	AccessToken string
+	AccessToken     string
+	RootNamespaceId string
 }
 
 var config = driver.Config{