Implement difficulty evaluators in the osu! mania ruleset
As it's possible and matches convention with other modes (excluding catch), I've gone ahead and taken the time to implement mania difficulty calculation evaluators in order to compartmentalize the strain skill a bit, and really show just how barebones mania calculation currently is. Values should match live.
This change should facilitate a lot of further changes to mania star rating, which I'm excited to see.
!diffcalc RULESET=mania OSU_A=https://github.com/ppy/osu/tree/pp-dev OSU_B=https://github.com/ppy/osu/pull/33411
Target: https://github.com/ppy/osu/pull/33411 Spreadsheet: https://docs.google.com/spreadsheets/d/1eiJ4F9Wvk5zeb8gZ0JDDj_xv6X1SDLHqLA7EU6xB66g/edit