Increased XP Weekend Summary Guild & User

[scottbucher]

Feature:

• At the end of an increased XP weekend, Alpha Bot can post a summary of how much XP was gained across all users in the server
  • Maybe could have stats like "User who gained the most XP", "User who leveled up the most", etc.
• A button can be attached to the increased XP weekend has ended message, which a user can click and get individual stats about how much XP they gained over the weekend (and any other stats like time in voice chat, though this would require additional database changes)

How (Proposal):

• Each GuildUser would have a new field, called something like "XpAtStartOfWeekend" (If we added more stats like time in VC or messages sent, we could make this new field an XpWeekendStats object and store more information). When an increased XP weekend starts, each user will have this new field set to their current XP amount, then, at the end of the weekend, it's a simple diff
• This system should integrated into the in memory caching we have for the XP system so we aren't bombarding the database