Improve input precision for midi

[nathanleiby]

Want to capture the EXACT timing of the midi note for use in timing.

Today, or timing is flattened to the nearest Macroquad game frame.

The UserHit model should include real ClockTime and (computed from that) corresponding beat.. this way we can determine "age" of a beat and expire it if needed (from looping perspective). Currently, UserHit is just re-using Voices as its data model

By capturing raw timing of midi vs frame (midi is not captured in game thread), it should be possible to determine how far off it is. compare midi time vs frame start time to compute a lag. I've built a prototype of this approach here: https://github.com/nathanleiby/input-timing

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Could Macroquad itself support high precision input? This could help for Keyboard intput, too.

• high precision input Design discussion: high-precision touch/mouse input not-fl3/macroquad#1 vs per frame
• maybe could PR this? Precise input not-fl3/miniquad#117