jdupes integration

[straxhaber]

If you're interested in using this to deduplicate files on your disk, you might want to check out https://github.com/jbruchon/jdupes. It supports creating clonefiles with duplicates via the -B/--dedupe flag. Note that the MAN page incorrectly says this depends on btrfs, but it supports both btrfs and APFS since around v1.17.