SharpSpectrumVAE but XL WOO!

Someone (cough FallenIncursio cough) asked if I could make it for SDXL and I did.

Since the original SDXL VAE is already pretty good, you won't see much difference, instead you get contrast and colors™️. (I do have one that does more, but it also comes with some quirks normal users shouldn't have to get annoyed with, so won't be releasing that publicly, unless I find a way to fix those)

Yes, it will work on all SDXL derivatives. That means PonyXL as well.

It is based on the FP16-fix of the SDXL VAE, so it shouldn't produce NaNs hopefully™️.