GPU-accelarated particle renderer for ParticleFX

[paroj]

currently we do all particle updates on the CPU, which is costy for millions of particles.
We could use transform-feedback instead.

This would also allow depth-buffer based collisions.

https://gpfault.net/posts/webgl2-particles.txt.html

[paroj]

https://arm-software.github.io/opengl-es-sdk-for-android/compute_particles.html