[Feature request] 8x scale

[Disonantemus]

I've tested 8x NMKD Typescale and 8x TGHQFace, both are ESRGAN.

Using this command:

$ realesrgan-ncnn-vulkan -i in.png -o out.png -m 8x_NMKD-Typescale_175k -s 4

Because the model is 8x, upscale seems to work in the output image, but is glitched.

in.png:

out.png (glitched):

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They are a more 8x ESRGAN models (and also 16x) that maybe are easy to patch.

The model "8x NMKD Typescale" is one of the best to upscale text, and is only available in 8x.