Add a custom SoundCloud player

[slxdy]

For context, I'm very new to Udon and this repo, so I might not be aware of all the limitations.

On base Unity, adding a Soundcloud player is very straight forward. You can interact with the SoundCloud API v2 to get an mp3 stream for any track URL, then turn it into an AudioClip.

If this idea is approved, I can create a PR and add it. Also please let me know of any limitations I should be aware of when working with Udon.