Add `review` mode to `image_manual`

Yes, at the moment, you should see a message like "Vote for this feature on the forum" if you're trying to use review with image data :smiley:

One reason is that we haven't really found a satisfying way yet to display conflicting conflicting image annotations. Displaying all variations together can get pretty messy – and it's kind of unclear how to handle subtle differences. If you're annotating text and tokens, there are only so many possible variations, but if you're actually drawing bounding boxes, they're pretty much always going to be different (at least, it's super unlikely that two people will draw a box with identical pixel coordinates). So there probably need to be additional settings to define those things.

The input and output format are the same, so you can always export your existing annotations as JSONL, load them back into the recipe and go through them again. You could also write a custom recipe that loads in the data and creates a new example for each bounding box, so you can step through them one by one if that's easier.