[Feature]: Add Pixelsmith support

[RedStingray]

Feature description

Add Pixelsmith, an upscaling technique that uses cascading patches to reduce artifacts in the upscaled output.
Official code is here: Pixelsmith github
Link to paper is here: Arxiv page
Paper claims that it is state-of-the-art in both image quality and generation efficiency.

Version Platform Description

No response

[vladmandic]

author should make it portable instead of having hacks like this:

Copy/paste autoencoder_kl.py and vae.py in your environment (f.i. home/user/miniconda3/envs/pixelsmith/lib/python3.11/site-packages/diffusers/models/autoencoders/)

this is nonsense and i'm not going to do the work for them - if repo is updated so code is actually portable, i'm open to integrating it.

[RedStingray]

Understood, thanks for looking at it!