`results - inspect`: add button to save masks for all images for all spectra?

[Claudius-Appel]

This would allow saving the masks for each spectrum and each image.

However, this is quite expensive computationally/time-wise:

$N\text{total-masks}=k{images}\times n{spectra}\times b\text{boolean normal or extreme}$

For 32 images and normal GFA-procedure with 4 spectra, that results in

$N = 32 4 2 = 256$

images at 6000x4000 pixel resolution. Each image must be generated manually, sequentially, and thus this will take ages.

I suppose this could be parallelized across images, the same way the main analysis pipeline is - but idk.

[Claudius-Appel]

Spectra can also not be masked collectively in a single image as they might overlap (e.g. bex_drought_HSV and bex_complete_HSV)