Coordinator should see which images were chosen as favorites

[atsirlin]

We need an endpoint that will tell the campaign coordinator which images were chosen as favorites. The idea is to feed this information into the csv-report produced by the "Download results" button. Presently, this csv-report contains the average grade and the grade given by each juror. We should at least supply one more column to say whether the image has been favored by someone.

The bigger idea behind it is to track selected images that were particularly liked by one of the jurors. The first 'yes/no' round may include thousands of files, which makes it easy to miss high-quality images if one of the jurors accidentally presses the No button. Therefore, our jurors were asking for this option of choosing their favorite images that can be tracked during the grading process.