[annotations] add view to show a user his/her summary of annotations (per set)

[vsoch]

line ~234 of labelinator app views.py, I am using a distinct=True

 # Get the concise annotations
    annotations = Annotation.objects.filter(reports__report_id=report.report_id).annotate(Count('annotation', distinct=True))
    annotations = summarize_annotations(annotations)

and we need to make sure this preserves counts for distinct annotations (meaning across users).