Add AuraSR/GigaGAN upscaler

[isidentical]

AuraSR is a new open source upscaler for synthetically generated images specifically (doesn't do restoration etc for now, but v2 might do it) that is based on lucidrains/GigaGAN. Might make sense to add it, there is a super simple / self-contained pytorch implementation here: https://github.com/fal-ai/aura-sr/blob/main/aura_sr.py

[zelenooki87]

They updated model to v2
https://huggingface.co/fal/AuraSR-v2/tree/main
It is not bad as before :)
Could oyu add support?

[zelenooki87]

@isidentical
With a little difficulty, I have successfully converted the AuraSR v2 model (an open-source alternative to GigaGAN). Version v2 is quite decent, unlike the first version which produced many artifacts. The fp32 model would have exceeded 2GB in size and wouldn't fit into a single file. So, I created an fp16 version.
https://mega.nz/folder/8kA2mKzZ#LWahzxk-447JaRSx3Xp_OQ