[Request]: Import filesystem from tarball

### Feature or enhancement request details

Currently there is support for `load` from layers, but not `import` from tarball.

A workaround is to do a container build, but it is handy to have a oneliner for it...

```Dockerfile
FROM scratch
ADD rootfs.tar /
```

As in `docker import`

(also including .tar.gz)

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct