Render preview images to fit search result view
- minimum height and width to allow fitting ->could mean upsizing
- center in surrounding box
- Fix lightbox
(from redmine: issue id 1178, created on 2018-08-30tgradl, closed on 2019-05-14)
(from redmine: issue id 1178, created on 2018-08-30tgradl, closed on 2019-05-14)