delta-find: finish reworking the snapshot logic and drop more layer...
delta-find: finish reworking the snapshot logic and drop more layer
The refining logic only applies to the snapshot logic, and this is now all
contained in a dedicated method.
Along the way, we drop the refined_groups // raw_groups layer as they no longer
make sense. The result is a more explicit `iter_groups` method.
This conclude the splitting and simplification of the groups generation.
We are now ready to dispatch this in more diverse classes.
