Update raw-window-handle to 0.4

[17cupsofcoffee]

This is required for Rust-SDL2 to work with the latest version of WGPU.

This would usually be a breaking change, but thankfully raw-window-handle have used the semver trick to do a compatibility release of 0.3. This means that any 0.4 HasRawWindowHandle also implements the 0.3 HasRawWindowHandle (hence why the WGPU example hasn't broken as a result of this change).

I did try to update the WGPU example too, but I don't know the API well enough to do so.

I have tested this on Windows and it seems to work - I don't have any way of testing other OSes, but the API changes seem fairly uniform, so hopefully it should all be fine? Will wait and see how the CI build goes :)

Summary of changes:

• Loads of stuff got renamed.
• All of the structs are non-exhaustive now, so we can't use the .. syntax to build them.

[Cobrand]

Thanks!

[toyboot4e]

Could you run cargo publish?

This is PR is nice and resolves my build issue, but it looks like the latest rust-sdl2 is not available yet.

I can use the master directly though. Thank you :)