Update webgpu classes to use dawn v7037

- closes vtk/vtk#19524
- due to changes in API upstream, some code change is necessary to be able to compile with dawn v7037.
- callbacks now have `wgpu::StringView` instead of `const char*`
- all status enums in callbacks are C++ style enums instead of C style enums
- all async functions return a `wgpu::Future` which can be passed into `wgpu::Instance::WaitAny`
- uses callback mode `AllowProcessEvents` for buffer async mapping