Enhancement: expose libwebp preset option for control over lossy WebP output

[rawriddims]

Sharp is very good, and has mozjpeg as well. So i decided i will use it, after have been trying almost everything else.
But there's just one little thing I'm missing. In CWebP there is a magic option: the -preset string with different values for photo, picture, drawing, icon, text. Is it possible to have some more .options for webp with Sharp in the future?

[lovell]

The WebP preset option for lossy images is supported by libvips but not yet exposed by sharp, so this would make a good enhancement.

[rawriddims]

I'd love that

[lovell]

Added in v0.32.3 - see https://sharp.pixelplumbing.com/api-output#webp