Reduce number of API calls for upcoming tournaments

[dathbe]

Really once per day is enough.

[dathbe]

Updated to pull as often as rankings (default 4 hours).

As of now, there is still a weird quirk in the code that requires an initial pull of leaderboard data even if user does not want to show leaderboards (showBoards = false). It's only one pull on startup, but I'd like to eventually remove the need.

Currently, upcoming tournaments are always pulled, so maybe the module startup can be triggered off that instead.