Additional data loaders

[dariarom94]

We need to add additional "ground truth" loaders, at least for

1. Spatial proteomics (Daria):

   • CODEX on the same/aligned slide
   • Xenium with protein panels

2. H&E with annotations (Florian)

[dariarom94]

For the proteomics module: take the mask from xenium segmentation as an input
aggregate signal intensity: take an average