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 could do but I thought I would pass it in as it is a bit more readable and that field is being updated in the method so getting hold of the value would be line position dependent.