Use Taxonomy hierarchy as folder structure

Thanks for your feedback, @MegaChriz.
Indeed you are right that this solution is not the best one and doesn't cover all the cases.
The main reason I added this patch is to cover my specific case and start a discussion on how this can be improved on a module level.
Do you think creating this custom token should be handled in this module or it's out of scope and each project should prepare such if they want to achieve the above case?

Another thing that comes to my mind is to use the options array and pass the join parameter there like this:

$value = \Drupal::service('token')
      ->replace($value, $data, ['join' => '/]);

The token replacement logic accepts it:

  $join = isset($options['join']) ? $options['join'] : ', ';

Then we can have a settings checkbox that says "Replace commas with slashes", similar to the "Remove slashes (/) from tokens" setting.