Investigate new sound track generation

[xezon]

Potentially we can use AI now or in the future to generate new tracks from the existing USA, China and GLA soundtracks. This way we could deliver a bit more fresh content for the game with small effort.

https://google-research.github.io/seanet/musiclm/examples/

[ImTimK]

Quality standard of ZH soundtracks are too high for the stages AI is in now, it will take a long time before AI can generate compositions and mixes like this, if ever.

[MTKing4]

We can try at least