Diffusers model adapters

Currently not able to load diffusers models as is due to difference in layout, viz. for SDXL if I try to load [SDXL FaeTastic](https://civitai.com/models/129681?modelVersionId=291443) it will error out following the code in [candle-examples
](https://github.com/huggingface/candle/tree/main/candle-examples/examples/stable-diffusion)

On investigating I see that the safetensors kv layout is entirely difference from what's there in the default loader, which follows seperate model file layouting rather than a monolith.

I request having alternative loader methods to load these kinds of models in `candle-transformers` package.