[feature] ability to restore as tar stream into stdout #191

Would be great if it were possible to do partial restores/full restores into stdout, formatted as a tar stream, allowing easier and faster integration into third-party wrappers

kopia and restic have something like that, and it shouldntbe too complex to implement here:
https://kopia.io/docs/reference/command-line/common/restore/ --mode tar
https://restic.readthedocs.io/en/stable/050_restore.html#printing-files-to-stdout -a tar