add support of 32-bit images

[ekatrukha]

Hello @tpietzsch,

I've added 32-bit image support, both for simple volumes and multires.
I am providing a testing example here.

It generates 8-, 16-, and 32-bit (red, green, blue) in "SimpleVolume" version (top row)
and in cached CellImg versions (bottom row).
It draws a gyroid with intensity values for each type (0 : 255, 0 : 65535, -1 : +1),
sets display range to these values too.

20251211_multiple_types.mp4

In the blue bottom cube (float multires), you can see some background initially, before the full loading.
It is not an artifact; it is basically zero values,
since the range is -1 to 1 (I wanted to make sure negative values work well).

I think it would be nice to have all "basic" real types to be supported.

Maybe @NicoKiaru has time to test it?
You can run the recent CLIJ deconvolution with this option.

Cheers,
Eugene