SDL GPU: Add a way to enable GPU based validation

[Arcnor]

Currently when using debug mode GPU based validation is not enabled (because it's very expensive), but this is helpful to debug certain issues, so will be nice to have a way to enable it when required using a hint or a prop. Cc @thatcosmonaut

[thatcosmonaut]

I'll add a prop for this on device creation, not urgent to be done before 3.2 release.