Initial attempt at storing aggregate data for achievement stats

[Jamiras]

This PR simply adds the additional aggregate columns and implements the functionality to update those aggregate columns. I want to run this on the server for a while to ensure the aggregates keep accurate tallies before switching over to use them.

After validation, several queries can be updated to use the aggregate data instead of recalculating it every time it's needed. This will provide significant performance improvements for games with lots of players - aggregating the Awarded table is very expensive and has to be done for every achievement in a set to determine the number of unlocks for each achievement.