release: Prepare Vagrant cloudware images for building as non-root

Add metalog entries for various files. This is a bit incomplete as
pw(8) doesn't yet have support for emitting metalog entries, which we
need since it's used here to create an interactive user.

Reviewed by: emaste
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D52456