Add `VAEImageDecoder` for StableDiffusionV3

[james77777778]

Numerics check: https://colab.research.google.com/drive/1YsWvZ0NBINDgdqipsldso1Y1NKJUDkUf?usp=sharing

Future works:

• [x] Implement CLIPPreprocessor
• [ ] Wrap CLIPTextEncoder and T5XXLTextEncoder for the use in StableDiffusionV3
• [x] Implement VAEImageDecoder
• [ ] Implement MMDiT
• [ ] Implement StableDiffusionV3 (inference model)

@divyashreepathihalli @mattdangerw @SamanehSaadat