[Feature Request] Add import/export support for MSU-1 PCM audio

[VideogameScrapbook]

There have been many MSU-1 looping audio packs created for SNES games (https://www.zeldix.net/t2684-alphabetical-list-every-snes-msu-1-hack). These packs can be used as a source for easily creating other looping audio formats for use in other games or audio players. In addition, looopable audio on Smash Custom Music could be used as a source to go the opposite direction, acting as a source for new MSU-1 hacks for SNES games.

It turned out to be low effort to add import/export support for this format in LoopingAudioConverter. You can see the commits and more information here: https://github.com/libertyernie/LoopingAudioConverter/issues/17