Adjust display of braces and brackets

[Danielku15]

Currently alphaTab always renders a bracket in front of the system which is not always desired and correct. Including some customization options the defaults also should be better:

Guitar Pro

We should respect the setting in Guitar Pro files (stylesheet):

For grand-staffs we should rather render a brace.

Multi Track

Normally there should only be a line connecting all systems.

In multi-track display it should be an option to define the brackets and their display. Brackets should group multiple instrument of the same family. This should be rather a user/dev input than auto-detected.

References

• https://archive.steinberg.help/dorico/v3/en/dorico/topics/notation_reference/notation_reference_brackets_braces/notation_reference_brackets_braces_c.html
• https://sites.coloradocollege.edu/musicengraving/engraving-convention/braces-and-bracket/#:~:text=Braces%20are%20perpendicular%20lines%20with,violins%20of%20a%20string%20quartet.
• http://donrathjr.com/brackets-braces-music-theory/
• https://www.areditions.com/blog/post/protip-group-brackets-and-braces