[Feature Request] Support running multiple independent upscalers on the same original image in Extras

[PZAragon]

This request is about being able to select many/all upscalers in Extras tab->Single Image and then batch-run each upscale one by one on the original image.

This request is because the best upscaler is highly dependent on the image content, especially when upscaling to very large dimensions. This ends up being a try-and-error approach on each image.

To clarify, the intention is not to run one upscaler on a previously upscaled image but for each upscaler to upscale the original image.
For example, having an image with 512x512 resolution, then setting 2x resize, and selecting "Lanczos", "BSRGAN", "Lollypop" upscalers, would result in three images, each 1024x1024, and each one an upscale of the original 512x512 image using one of the selected upscalers.

[barrubba]

Completely agree.. Will be very useful.. Very image dependent.. So trying different upscaler in a click will be a must