Add property to toggle anti-aliasing on Path elements

[tronical]

This enables working around bugs in GPU drivers. Especially the GC7000UL
plus its driver on imx8mp has been observed to sometimes horribly degrade in performance when Skia renders anti-aliased paths (when a function like gcoSURF_BlitCPU shows up at the top of perf that's a bad sign).

[ogoffart]

I wonder if one could reuse the image-rendering enum here.
But I guess the name is different.
Imone thought I had is to extend the enum with a "default" that would be the default so the software renderer could default to pixelated. That's not possible with a bool

[tronical]

I wonder if one could reuse the image-rendering enum here. But I guess the name is different.

Yeah, same conclusion here. Different fit/purpose. image-rendering affects how the image is rendered when scaled, while this is about the Path rendering, regardless of the size.