update table readers and writers to ngff table proposal

[giovp]

hi,

with this issue, I'm referring to the discussion here: https://forum.image.sc/t/roi-annotations-and-tracking-information-in-ome-zarr/65975/4

It should be straightforward to change the current code in the notebook to readers and writers with the correct .zattr, you can see and example for

• writer
• reader

the logic is that we store the metadata necessary for the table specification: region, region_key and instance_key in the adata.uns slot, and also redundantly in the .zattrs. However, at read time, we only take it from uns (but it should be straightforward to also read it from the .zattr metadata).

let me know if you encounter any issue or for any clarification

[DrKenHo-crick]

Thanks @giovp we shall try to check it out in the next few days and see how that works.