Support mesh output in ShapEPipeline #3986

Is your feature request related to a problem? Please describe.

ShapEPipeline was added in diffusers==0.18.0, which is nice, but currently it doesn't support outputting the generated result in mesh formats and only supports outputting rendered video in a specific way like this:

With the original Shap-E implementation, we can get output in mesh format as you can see in this Space.

I think it would be awesome if we can do the same thing with diffusers implementation as the original implementation.