feat: added webgpu tensorflow example

[MendyBerger]

Adds a TensorFlow.js example running on top of wasi:webgpu

Needed before merging:

[ ] next wash v2 rc (needs webgpu adapter info)
[ ] replace wit-deps with wkg WebAssembly/wasi-gfx#63
[ ] investigate a memory leak at the end of encoding
[ ] investigate pretty major performance regression while refactor/cleanup
[ ] slightly better ui with example image

Other external PRs that would allow removing some hacks here:

[ ] unjs/unenv#540
[ ] tensorflow/tfjs#8639
[ ] bytecodealliance/ComponentizeJS#324

Other comments

• location.search is polyfiled to an empty string because tf assumes that's it's available.
• navigator.gpu is first set to empty an object at initialization so that the check if webgpu is available succeeds, and is later at runtime overridden with the real gpu object from wasi-gfx-js