Multi-schedule management

[BlieNuckel]

Update the current system for fetching and combining multiple schedules to simply use Kronox's built in ability to fetch multiple schedules at once.

This should hopefully allow us to cut out a lot of the pre-processing that's taking up time right now and simply do a basic fetch + drawing UI.

[BlieNuckel]

So this was a huge fucking mistake. Would still be nice if we could integrate the multi-schedule fetching directly from Kronox, but with our current in-app caching system there are fundamental clashes between the data structure and how we'd actually implement this. Gonna leave the issue open on low prio, but I don't see an immediate way we'd be able to put it together without some larger refactors on the data side of things