Stored overall ballot score

Stored overall average score from the judge ballot summary. The summary stores 330 ballots and 3 judges. overall_avg_score is 1.58. The three stored judge averages are 1.07, 1.57, and 2.11, each on 110 ballots. Their mean rounds to 1.58. With one stored score, the bar is full. This score is separate from arena Elo. A missing score stays off the page.