Images loaded during curation should not be visible during training/prediction.

Currently, if we load images during curation, they are put into the napari viewer and they persist there even when switching to training and prediction.

We should make it so that if the user switches off the curation tab, the images disappear, and if they go back to curation the images are re-loaded into the napari window.

(if we try predicting on an image thats loaded from curation, there's no path available for that image and we end up getting an error, this change would prevent that)