Handle plates and bioformats2raw URLs

[will-moore]

With the same logic as in ome-2024-ngff-challenge, pick the first image from bioformats2raw or plate and use that for thumbnail.

[lubianat]

One note is that the OME-Zarr spec says for the bioformats2raw laout spec

Conforming readers:

SHOULD make users aware of the presence of more than one image (i.e. SHOULD NOT default to only opening the first image);

https://ngff.openmicroscopy.org/0.5/index.html#plate-md

I know this is a slightly different case, but we can take that into consideration

[will-moore]

I can see a use-case for a couple of different behaviours...

• 1 Only show the first thumbnail - useful for speed but doesn't make users aware of other images
• 2 Show some composite image - e.g. First 4 images tiled into a thumbnail
• 3 Show a single image with the image count overlaid - or some other info or mark that indicates there are other images

In the ngff-2024-challenge, we are doing 1. It would be fun to have a go at 2 and/or 3 - e.g. just create up to 4 thumbnails with existing logic, then stitch them into a single RGB image.
I could imagine an option that allows you to specify the default behaviour, although we may want to try and get #20 done first, so we don't have quite so many arguments.