[Direct Transfer] Add the dt_hide_personal_space option to hide the "Personal space" remote location

Allowing transfers into the Personal Space folder can be problematic. So we added a new option to hide it from the Direct Transfer window: [dt-hide-personal-space] ( https://doc.nuxeo.com/client-apps/nuxeo-drive/#dt-hide-personal-space ). The option can be set globally from the server configuration, and it will be taken into account almost instantly by all clients without requiring a restart of the application.