Move all cropped images to folder inside processed

[Max-Gamill]

Is your feature request related to a problem? Please describe. Users find it frustrating to look through each individual image folder to obtain the individual crops. This makes it easier to look through populations.

Describe the solution you'd like Two things are needed for this:

1. The cropped images need to be moved to the "core" set but only the images (not the binary mask and hybrid)
2. These images need to go into their own folder under processed called "cropped_images"

Note: As this may be used when changing the masking parameters, more/less objects may be found meaning that duplicate/newer objects with a different grain number can be saved. Thus, the user needs to remove the current cropped images folder before changing masking parameters and re-running. It was decided that the best way to do this was NOT to delete the folder if already there, but instead, prompt the user with a warning to delete data.

Describe alternatives you've considered N/A

Additional context Add any other context or screenshots about the feature request here.

[ns-rse]

See suggestion of making this configurable in #709.