Generate wrappers & use cgo hints

[oliverbestmann]

Using #cgo noescape and #cgo nocallback when possible allows the go compiler to pass pointers to heap values. This leads to it not needing to allocate when calling into wgpu. It only needs to allocate once for the returned wrapper object.

Before:

BenchmarkCreateView-10         	  630223	      1758 ns/op	      96 B/op	       3 allocs/op
BenchmarkCreateBindGroup-10    	  290613	      3642 ns/op	      32 B/op	       2 allocs/op
BenchmarkBeginRenderPass-10    	   32133	     44466 ns/op	     112 B/op	       6 allocs/op

After:

BenchmarkCreateView-10         	 1609491	       785.6 ns/op	      16 B/op	       1 allocs/op
BenchmarkCreateBindGroup-10    	  270481	      3702 ns/op	      16 B/op	       1 allocs/op
BenchmarkBeginRenderPass-10    	   27547	     36898 ns/op	      64 B/op	       3 allocs/op

[oliverbestmann]

@rcoreilly if you could have a quick look and check that nothing breaks on your side, that would be great. Otherwise I'll merge it later today or tomorrow and cleanup the pieces later :)

[rcoreilly]

if v.view.data != nil

This doesn't even compile!

[oliverbestmann]

Yea I fixes that already. Sorry for that. One of those: "okay everything works. Let me create a PR. Wait, let me add this one if here and then push it"

[rcoreilly]

Yep everything seems to work in cogentcore!

[oliverbestmann]

Thanks. I'll have a look at why it doesn't compile in Mac and wasm in ci later today and continue with the approach.