Improve output of Gold Image Processing command

[yeraydavidrodriguez]

Currently, the librarian does not support verbosity levels selection: only one "standard" log level is used. The information displayed in this level needs to be improved:

This is the typical output of a gold image processing command run:

The output information produced by the librarian is mixed with DVC output, and although each one of the images processed is referenced (many times), not all processes are shown (commits are omitted), and the order is not very clear ("new image found" is shown at the end, and some unexpressive lines with just the ✓ and the filename are shown at the beginning)

We should decide which kind of information is to be displayed, how, and what verbosity levels should be offered to the user to choose from.

This is my preliminary proposal for a "high verbosity" level:

Searching for new gold images...
    000005-32.600.2.tif gold image found
        ✓ Pulling image file from DVC storage 
        ✓ Validating image name and path 
        ✓ Checking image dimensions 
          Image dimensions are 1920 x 1278 
        ✓ Generating base image
          Image file data/000005/42/000005-42.600.2.tif successfully generated 
        ✓ Pushing base image to DVC
        ✓ Committing DVC files to repository
          Commit 13A56B2 successfully created
        ✔ Base image 000005-32.600.2.tif processed successfully
    000005-32.600.2.tif gold image found
        ...
Searching for modified gold images...
    No modified images found
...