tar: Move to the utilities package

tar(1) is not a core runtime utility; in particular, nothing in
/etc/rc.d/* requires it. Move it to utilities, which is also
where cpio(1) lives.

This removes the dependency from runtime to libarchive.

Approved by: re (cperciva)
MFC after: 3 days
Reviewed by: manu, emaste
Sponsored by: https://www.patreon.com/bsdivy
Differential Revision: https://reviews.freebsd.org/D53059

(cherry picked from commit c0f17d637a4ab1e5dcae6b931623b7b0ee5bece2)
(cherry picked from commit c6a19aed69168d2fdf5ab3d77470b5cf91152eae)