Numbered Music Notation - Chords and Multivoice

[Danielku15]

Follow up of #2317

We implemented Numbered notation mainly following the Guitar Pro behavior. But Guitar Pro lacks the correct display of chords or multiple voices in numbered music notation.

Unfortunately there is not much public documentation around how overall the numbered music notation is supposed to look.

Chords
Chords can be transcribed by vertically stacking the notes, with the lowest note at the bottom as with Western notation. Each note has its own octave dots, but only the lowest note has the length lines (next section).

Arpeggiated chords are notated by writing the standard Western arpeggiation symbol to the left of the chord.

Chord symbols such as Cm may be used if the exact voicing is unimportant.

https://en.wikipedia.org/wiki/Numbered_musical_notation

alphaTab should be extended to show chords accordingly.