Add support for 3d viewer with textures

Need to add support for 3d models with texture. This would involve:

1. Adding support for upload and storage of textures
2. Implementing a viewer that can use textures.

We should consider extending the existing ThreeJS-based 3d viewer as well as adding support for DPO Voyager (https://smithsonian.github.io/dpo-voyager/explorer/usage/)