PUTTMOON: Add audio modding support for the MIDI versions of the tracks in Putt-Putt Goes to the Moon

[SomeRandomHEFan]

A while ago, I updated the Bandcamp release of Putt-Putt Goes to the Moon's soundtrack to support playing it in the actual game via ScummVM's audio modding support. It can be found here: ​https://thefatmanandteamfat.bandcamp.com/album/putt-putt-goes-to-the-moon-remastered-soundtrack

However, I found that while ScummVM technically offers audio modding in the game's DOS versions as well, this only covers the sound effects and voice acting. The music can't be modded because it's in MIDI. I'd assume it's the same for early Mac releases of the game.

I realize that the vast majority of people who play this game nowadays use the Windows version, but the DOS version has a few slight advantages over it, so it would be nice if it could also be supported.