podman could benefit from stronger typing with some of our methods and
functions where uint64s, for example, are used because the unit of
measurement is unknown. Also, the need to convert between storage units
is critical in podman and this package supports easy conversion as
needed.
to start, we implement the storage units (bytes, KiB, MiB, and GiB)
only.
Signed-off-by: Brent Baude <bbaude@redhat.com>