Generate max score per chart and calculate rank from score percentage #9

For each chart, generate its max possible score. Use the formula from the practice sheet to calculate a player's rank based on their score as a percentage of the max.

This should be displayed in the post-match score thing.

References:

• SRTBEditor can calculate the max score of a chart: SRTBEditor/scripts/diagnostics.js line 252
• Practice sheet percentage formula: PERCENTAGE=TRUNC(SCORE / MAXSCORE, 4)
• Practice sheet rank formula: I2=IF(PERCENTAGE>=0.9975, "S+", IF(PERCENTAGE>=0.975, "S", IF(PERCENTAGE>=0.95, "A+", IF(PERCENTAGE>=0.9, "A", IF(PERCENTAGE>=0.8667, "B+", IF(PERCENTAGE>=0.8, "B", IF(PERCENTAGE>=0.75, "C+", IF(PERCENTAGE>=0.65, "C", IF(PERCENTAGE>=0.55, "D+", IF(PERCENTAGE>=0.5, "D", ""))) )))))))