Custom font and spacing configuration for lyrics

[Danielku15]

See #2370 (comment)

Problem

The readability of the lyrics in music sheet can be bad in some scenarios and it is desirable to make adjust the font size for better readability. At the same time, multiple lyric lines are hard to differenciate as they are quite close.

Current Behavior:

1. alphaTab uses the general effectFont which does not allow making specifically the lyrics larger.
2. The lyrics lines are spaced using the font size which can lead to narrow lyric lines or even overlaps.

   alphaTab/packages/alphatab/src/rendering/glyphs/LyricsGlyph.ts

   Line 32 in 0730fd7

   canvas.fillText(this._lines[i], cx + this.x, cy + this.y + i * this.font.size);

Desired Changes

1. alphaTab should provide individual font properties for the different effects instead of having one general font setting for all.
2. alphaTab should rely on text measurement to determine the actual height of the rendered text. Additionally there should be a setting to allow increasing the spacing between lyric lines.