Std length bonus fix by calculating consistency for each skill

[TheDark98]

The change modifies:

For all gamemode:

• New value, DifficultyFactor, to calculate the proportion between the average difficulty of hits and the maximum hit difficulty, represented by a value from 0 to 1.

For standard only:

• DifficultyFactor for aim and speed skills.
• New PP bonus calculation.
• New lenth bonus formula.

taiko (separated here: https://github.com/TheDark98/osu/tree/Length-Bonus-Fix-Taiko)

mania (separated here: https://github.com/TheDark98/osu/tree/Length-Bonus-Fix-Mania)

[stanriders]

1. Please at least make sure your PR compiles before submitting
2. Commit history is full of unrelated stuff
3. No code quality, changes are sprinkled all over the repository for some reason (why are there changes in a general PerformanceCalculator??)
4. This doesn't seem to fix the length bonus at all (checking on a test map, 80s of filler and 20s of high difficulty gives roughly the same pp as just 100s of high difficulty) and instead randomly deflates values
5. Replace the length bonus with a new bonus dependant on object difficulty #30924 does pretty much the same concept (making length bonus be aware of the map difficulty)

So far this PR is pretty much unacceptable

[TheDark98]

I need to revise the factor calculation because dividing by the maximum difficulty doesn't produce the expected results and yields an incorrect value.