An option to generate missing previews and thumbnails

Please introduce a simple option to generate missing previews and thumbnails.

Currently, the only way of making Capture One generate missing previews for a whole catalogue is to regenerate previews for every single image in the catalogue, which will potentially require an enormous amount of time.

And the only way of making Capture One generate thumbnails is to scroll slowly through a catalogue (thumbnails are not created along with previews). If you have a large catalogue this obviously isn't a very useful solution.

(See this thread also.)