Point sprites is not working with skinning/morphing

[mwestphal]

Describe the bug The point sprites mapper does not support skinning/morphing, it's a missing feature

To Reproduce Steps to reproduce the behavior:

1. Open the file using ./bin/f3d ../src/testing/data/SimpleSkin.gltf -o
2. Press space to play animation
3. Animation doesnt work

Expected behavior Animation works with point sprites

F3D Information Paste the content of f3d --version or f3d-console.exe --version on Windows: master