Implement Vulkan Wrapper

[ominitay]

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This commit adds support for Vulkan to the wrapper API. Use is similar to using the Vulkan bindings, using getWrapperPackageVulkan rather than getWrapperPackage, passing the Vulkan package obtained from vulkan-zig.

I'm not sure whether functions such as createSurface are appropriate to put in the SDL.vulkan namespace, or whether they should be conditionally compiled as functions in the namespace of (in this case) sdl.Window.

Feedback is much appreciated on this :)

[ikskuh]

cc @Snektron