Add delete option for directories in the file browser

On the web app, there is not an option to delete a directory and all of its contents. The assets must be deleted individually. I would like an option to delete a directory and thereby all of its contents. Thanks.

No files or tests are named. Start by locating the web app's file-browser directory actions and the entry point used to delete individual assets; trace how a directory and its contents are represented. Done means the browser offers a directory-delete option and the directory's contents are removed together.

Written by the indexing model from the issue text.