record entry returned by object class map export is no longer a dictionary of paths, but rather one path for object map

Now that RoiSet is in base, remove dependency on ilastik in its test; tests now open segmentation mask from file

Progress on testing classify_by method; need to pass preference of channel to patch generator without disrupting existing options to export RGB / multichannel stacks

Product methods call RoiSet directly; this is causing problems with multichannel ones where raw data is essentially re-issues to RGB channels

Some test coverage, those that are failing are because of issues propagating nested parameters to pydantic models