Refactor out taiko Peaks skill

[stanriders]

This change removes Peaks skill and moves all of the combined calculation into the taiko difficulty calculator. The idea is that having skills within skills isn't really a good design, especially since Peaks skill was calling processing manually instead of passing it through the main difficulty calculation abstractions, and also enables back osu-tools per-skill strain visualization since it assumes that skills will always be present in the DifficultyCalculator.Skills[] array

Actual difficulty/performance values shouldn't change and from my limited testing seems like values didn't change.

This also changes the way difficulty calculator fetch skills from hardcoded array indexing to skills.First(x=> x is RequiredSkill) which I'd want to change in all difficulty calculators eventually

[smoogipoo]

!diffcalc

RULESET=taiko

[github-actions]

Target: #28596
Spreadsheet: https://docs.google.com/spreadsheets/d/1-JzfCBqhSzL_zQutZZsfryC_R_M7dOsJSme18LSvQ3U/edit