lib/commit: Honor commit filter for libarchive --tar-autocreate-parents

lib/commit: Honor commit filter for libarchive --tar-autocreate-parents

This makes `ostree commit --tree=tar` honor `--owner-uid` and `--owner-gid`
for the root directory.

Prep for further commit filtering work, although mostly for the unit test cases;
this ensures we can use `ostree checkout` after autocreating a root directory.

Closes: #1104
Approved by: jlebon