refactor onnxruntime integration (#2042)
* refactor onnxruntime integration
* fix requirements.txt bug
* make style
* add support for textual_inversion
* make style
* add readme
* cleanup README files
* 1/27/2023 update to training scripts
* make style
* 1/30 update to train_unconditional
* style with black-22.8.0
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Co-authored-by: Prathik Rao <prathikrao@microsoft.com>
Co-authored-by: anton- <anton@huggingface.co>
