common-canvas stable-diffusion sdxl en non-commercial CommonCanvas StabilityAI mosaicML multimodalart Wauplin lhoestq text-to-image dataset:common-canvas/commoncatalog-cc-by-nc-sa dataset:common-canvas/commoncatalog-cc-by-nc dataset:flickr100m arxiv:2310.16825 license:cc-by-nc-sa-4.0 region:us