Enhanced music engine

[mysterypaintwo]

With the help of AI, the following was done:

• Audio engine was modified to treat "rest" as a true note cut; All vanilla songs now remapped to utilize rest2 in place of the original rest command, which is actually "release" and is the true behavior of rest2: Audibly, it is indistinguishable from vanilla, but the bytes are slightly different as a result.
• Label looping now exists as local, definable macros: Looping mml with [<data>]<number of times to loop> now genuinely saves ROM space. Unfortunately, the vanilla audio assets are untouched at risk of breaking anything...
• Default note lengths have been implemented into the audio engine too; Vanilla songs automatically apply where sensical at compile-time; If a song is not using the #VANILLA flag then it is custom, and default note length must manually be defined.
• All vanilla songs and sfx are now converted to this mmlgb/ppmck-inspired syntax; Documentation for the mml2wla syntax is provided at /audio/mml_documentation.md
• Discovered that pitch offset is indeed a command that exists in the vanilla audio engine; supported it in MML as @po<value>; documentation talks about this more
• mml2wla has been hooked and modified to integrate directly with the oracles-disasm Makefile, living at /tools/audio/. All the .mml files get compiled into .s WLA source files in the relative /bin/ directory next to their respective .mml files.

I've tested this fork for both games and it works great; at the very least, this solution now exists and can be used (or at least studied) to develop even cooler things for the games' audio!