Add "trash" action

[hadess]

It would be great if the tool could, in addition to deleting the file, support "trashing" the file, eg. putting it in the Trash directory as defined by the XDG Trash specification: https://specifications.freedesktop.org/trash-spec/1.0/

Alternatively, I would be happy if it was possible to move all but one set of duplicated files to a specific directory, that I could then trash manually.