Have rlottie save to plutovg

[K. S. Ernest (iFire) Lee]

https://github.com/Samsung/rlottie

I had a thought it would be possible to connect rlottie to plutovg. Not sure if it's a good idea.

Benefits is that if I can get plutovg to output Godot 2D Editor scenes. I can also get lottie via plutovg to do the same.