allow image to have segmentation ROIs embedded

## Use Case

Images that have segmented objects could include as data (or determine at run time) the bounds of the segmentation labels.
This would allow remapping data range intensities per fov instead of per cropped cell image, and also allow cropped cells to be determined directly from the loaded FOV.

## Solution

find data encoding that gets this information. add UX to actually use the information in the sample app: select ROI to crop from list of given ones.

## Alternatives

This task is related to the allowable input data formats. Does Zarr allow you to add a list of ROI bounding boxes? Does OME-TIFF?