Rewrite the UnrankableFinisherCheck and also add a TaikoUtils class

[hongaaronc]

Summary

Resolves #5

This PR fixes all the issues with the UnrankableFinishersCheck.

Approach

Added a utility class (TaikoUtils.cs) which has a bunch of easy methods for checking a note's relationship to a pattern:

• IsDon()
• IsFinisher()
• IsAtBeginningOfPattern()
• IsAtEndOfPattern()
• IsInMiddleOfPattern() (unused currently)
• IsNotInPattern() (unused currently)
• GetPatternSpacingMs()

These methods are implemented by following this logic:

1. Look to the previous and next adjacent notes
2. Get the spacing between previous and adjacent
3. Lower spacing side = part of the same pattern (so beginning or end)
4. Same spacing = middle of pattern

For the actual check, I've added several dictionaries to define the first snap divisor that counts as a violation in various cases, with a Problem severity version and a Warning severity version:

• maximalGapBeats : Triggered if the pattern is <= this snap divisor regardless of any other conditions
• maximalGapBeatsRequiringColorChangeBefore : Triggered if note doesn't have a color change before it and isn't the first note, and the pattern is <= this snap divisor
• maximalGapBeatsRequiringColorChangeAfter : Triggered if note doesn't have a color change in the note after it and isn't the last note, and the pattern is <= this snap divisor
• maximalGapBeatsRequiringFinalNote : Triggered if note is the final note in the pattern, and the pattern is <= this snap divisor

Testing

• Seems to work from everything I've tested. No known issues atm but feel free to test

[hongaaronc]

Maybe we could add 1/3 Muzu as a warning. Probably wouldn't do problem tho, since I think 1/3 finisher might make sense for some swing or 6/8 songs.

[hongaaronc]

Not ranked but I could see 1/3 + finisher being used like how I did in Muzu here (6/8 song). This is very low BPM though and 1/3 is practically used like how 1/2 would normally be: https://osu.ppy.sh/beatmapsets/1856271

Btw... on the note of slower BPM songs, should https://github.com/Hiviexd/MVTaikoChecks/blob/cab8008e4ca065d356311b16a2345fe8ff10e5ef/Checks/Compose/UnrankableFinisherCheck.cs#L184 use timing.GetNormalizedMsPerBeat() instead of timing.msPerBeat - to add BPM scaling?

I wasn't sure but I guess thinking about it more, I think it should probably?

[Hiviexd]

probably a good idea to consider bpm scaling for this

[hongaaronc]

Ok added both the BPM scaling and 1/3 + finisher warning.