diffusers safetensors art t2i-adapter image-to-image stable-diffusion-xl-diffusers stable-diffusion-xl arxiv:2302.08453 base_model:stabilityai/stable-diffusion-xl-base-1.0 base_model:finetune:stabilityai/stable-diffusion-xl-base-1.0 license:apache-2.0 region:us