Improve MIDI message scheduling

[Spacechild1]

I just noticed that you schedule MIDI messages on the tempo clock:

https://github.com/thgrund/TidalVST/blob/a625ad604ba79e7f790cb2d57a722da85c9c23f0/TidalVST.scd#L91-L97

For accurate timing, the MIDI messages should be scheduled as OSC bundles instead. For example:

~dirt.server.makeBundle(latency, {
    instruments[vstName].midi.noteOn(0, note, velocity);
});

~dirt.server.makeBundle(sustain + latency, {
    instruments[vstName].midi.noteOff(0, note, velocity);
});