`SurfaceCapabilities::present_modes` are not properly checked, causing vsync setting to not be respected.

[mkrasnitski]

I noticed that #424 checks that the selected present mode is supported and falls back to AutoVsync if it is not. However, on my system, the list of present modes reported by wgpu does not include AutoVsync nor AutoNoVsync. I'm not sure if this is always the case, but at least for me this means that AutoNoVsync has no effect, as well as PixelsBuilder::enable_vsync(false).

It would be better to special case AutoVsync and AutoNoVsync as the wgpu docs say they are supported on all platforms.

[parasyte]

That is unexpected. I understood "supported everywhere" in the wgpu docs to mean these would show up in surface capabilities. But I suspect it just means they are implicitly supported, and not literal capabilities that must be reported.