[BUGFIX] Sustains now give consistent scores [+ songScore as Float]

[xenkap]

Does this PR close any issues? If so, link them below.

N/A

Briefly describe the issue(s) fixed.

Sustain notes previously did not consistently give score-- it was all dependent on how long you held it for, regardless of when you started holding, disconnected from the actual length of the note. This caused sustains hit earlier to reward more points than sustains hit later, as well as other undesirable effects. This behavior is now fixed.

These demonstrations are done with a script that disables regular note scoring, leaving only sustain scores to count.

Before:

2024-11-05.22-25-03.mp4

After (VIDEO SLIGHTLY OUTDATED, 100% FIXED NOW):

2024-11-05.23-52-00.mp4

This PR places scoring behavior in Strumline, which may be undesirable.
An alternative approach would be to add a variable in SustainTrail.hx that tracks PlayState's last read on it, and then performing logic where it used to be done anyway. I tried this, but it didn't exactly work out...

This PR also changes songScore to be a Float, and all score-related scripting variables to Float as well.
All saving and displaying of the score still uses the integer using songScoreInt.
Written with the assumption that #3708 will be pulled. If it isn't, removals of offset corrections will be required.

[xenkap]

An alternative approach would be to add a variable in SustainTrail.hx that tracks PlayState's last read on it, and then performing logic where it used to be done anyway. I'll might make a separate branch for that later-- if I don't, well.

On second thought, this seems like the simpler approach. Working on it now
EDIT: Issues arise in the instance that sustainLength is positive one frame and negative the next. Nevermind then
(this wasn't even the issue i ran into-- for some reason, it just refused to give points outright... bwekh)

[Hundrec]

If done right, this could finally standardize scores across all attempts!
Please polish this up the best you can :)

[xenkap]

If done right, this could finally standardize scores across all attempts! Please polish this up the best you can :)

Thank you!! I'm not sure what much else I can do on the topic of sustains, since it seems to be 100% accurate now.
But talking about standardized scores, I'm not very sure about the 5ms input window for a perfect score, haha
Although that might be reasonable in other rhythm games. Haven't ever seen one with that strict of a window, though

[xenkap]

I just realized the after video shows me taking a score of 288 (goal: 275).
I've already fixed this, but since I recorded it before that, it doesn't appear so. Bwekh