feat: new guitar pro instrument set writing

[Danielku15]

Issues

Fixes #2467

Proposed changes

based on the changes of @L-Sun I further refactored the current code around percussion articulations.

The complexity of this PR shows how nasty the mapping close to GuitarPro is. its index-based articulation lookup (vs. an id lookup), and the historical problems scream for a rework. I'd with GP would use proper unique IDs for the articulations instead of an index and "input midi number" approach.

Generally this PR tries to prepare already some model areas for having a "articulation by id" approach.

• When exporting GP files we try to lookup any known articulation and additionally write the RSE information we have.
• For MusicXML we try to match articulations by the output midi number to allow file conversion flows to work.
• The general construction of the InstrumentSet is now moved to a dedicated component with the idea that the RSE information could be loaded from a template file in future.

On the way I discovered a bug that the NotationPatch was incorrectly applied as we have to use the Element name for identification.

This change allows using RSE until some extend. Some aspects of the effect chain are not in-place which can lead to strange UI discrepancies (e.g. RSE/SoundbankPatch).

Checklist

• I consent that this change becomes part of alphaTab under it's current or any future open source license
• Changes are implemented
• New tests were added

Further details

• This is a breaking change
• This change will require update of the documentation/website