qdev-properties: add getter for size32 and blocksize

qdev-properties: add getter for size32 and blocksize

Add getter for size32, and use it for blocksize, too.

In its human-readable branch, it reports approximate size in
human-readable units next to the exact byte value, like the getter for
64bit size does.

Adjust the expected test output accordingly.

Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528225516.1676602-8-rvkagan@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>