Output VGM recording

[denjhang]

I hope to add the ability to record VGM, it will be useful.

[Wohlstand]

Do you want to record real-time play/steam? or convert a MIDI file?

For the second case, it's reasonable task for libADLMIDI, I need to resume some works that was started by @freq-mod (Wohlstand/libADLMIDI#250). At the side of libOPNMIDI there is already VGM recorder was been made a while ago.

[denjhang]

I have been waiting for several years.

[Wohlstand]

Closing this as this task is more related to libADMIDI rather than to this bank editor.