Refactor lazy path calculation in OsuDifficultyHitObject processing

[Givikap120]

1. For some reason there was movement variable as well as movementLength variable, when only length was used. This was fixed.
2. Movement length was calculated by subtraction and calling .Length method. It can be calculated in one line with Vector2.Distance, making it more readable.
3. Some very scary multiplication formula was replaced with simple Vector2.Lerp call.
4. To represent changed functions variables was renamed respectively

This can trigger some floating-point precision errors
EDIT: ye, that triggers some very small errors around 8E-5. Even tho I didn't noticed difference on Star Rating in game. Even on Kaede.

[tsunyoku]

I'm not convinced that this really matters, but there's no harm in it either as long as sheets show that SR/PP differences are negligible.

[smoogipoo]

Tests will need adjustments.

[Givikap120]

I'm not convinced that this really matters, but there's no harm in it either as long as sheets show that SR/PP differences are negligible.

the whole sliders calculation looks way more intimidating than it should
so maybe some person who will read the pp code will have more willingness to research how it works

I don't sure this is necessary too
but after digging in the whole pp code I tried to change the things that was the most confusing

[smoogipoo]

!diffcalc

[github-actions]

Target: #30233
Spreadsheet: https://docs.google.com/spreadsheets/d/1S9jexujpdmeRVCs39Evp-MKuaco7Y_fWcyjqICEKFZg/edit

[Givikap120]

oops, this has outdated diffcalc version

[smoogipoo]

!diffcalc

[github-actions]

Difficulty calculation failed: https://github.com/ppy/osu/actions/runs/11791198882

[github-actions]

Target: #30233
Spreadsheet: https://docs.google.com/spreadsheets/d/15lVwe2IEO5xiB95Oow1vClW6Mv5W1qSLyfvotHgRHh4/edit

[Givikap120]

Target: #30233 Spreadsheet: https://docs.google.com/spreadsheets/d/15lVwe2IEO5xiB95Oow1vClW6Mv5W1qSLyfvotHgRHh4/edit

hm yea, this is definitely big changes, I will look into it

The base branch was changed.