Add id Software ADL format to NScumm.Audio.Players

[BenMcLean]

Id Software's ADL format is used for Adlib sound effects in the Commander Keen and Wolfenstein 3-D engine games. It is a completely separate format from IMF and from the Westwood ADL File Format. Instead of entire songs, it is intended for just playing short sound effects. It only uses channel 0, leaving channels 1-7 available for IMF playback.

I wrote a C# container and player for this format in my WOLF3D-Godot project and I may be able to base an NScumm.Audio.Players class on what I wrote there. I'll try to get a PR together for this sometime soon.