Support Vertex Animation Texture

[emadurandal]

References

• https://houdinifx.jp/blog/vertex-animation-texture/
• https://www.sidefx.com/ja/tutorials/unity-shaders-for-vertex-animation-export-tools/
• https://medium.com/tech-at-wildlife-studios/texture-animation-techniques-1daecb316657
• https://github.com/sneha-belkhale/vertex-texture-cache