Web UI does not allow for removal of a folder

The current way to delete a folder in the Web UI is to delete all files in the folder. This is clunky, slow, and unexpected. We should add a delete button in the UI.

Design

Added Edit and Delete buttons on the directory page. It's easy to find them.

When clicked Edit button, people can edit the directory name and commit the change in the modal.

When clicked Delete button, people can remove the directory after filling the commit message.