Fix up the ora2 scores affected by the track changes bug.

  For affected assessments:
    - Sets PeerWorkflowItem.scored = 0 if currently = 1
    - Recalculates the score for the submission
    - If new score > old score, update the Score.points_earned with the new score
I had a typo, should be PeerWorkflowItem.scored = 0

The peer assessment grading works by summing the median of the individual scores.