Update summary metrics

[katxiao]

Problem Description

Current, the summary metrics from the sdgym summary command are % coverage, avg time, avg score. We can update them to be more informative about the synthesizers' comparative performance and accuracy.

Expected behavior

Performance (time) metrics: One idea is to use a leaderboard approach. We can display how many times a given synthesizer had the best relative modeling time.

Quality metrics: TBD