[WebGPU] Implement async tensor api and event api (#22099)
* Only run webgpu CI on my fork
* Implement set_tensor_async
* Implement synchronize api
* Implement event creation and deletion API
* Cleanup
* Cleanup
* Comment out jobs for local CI run
* Add webgpu only workflow
* Delete .github/workflows/build-webgpu.yml
* Cleanup
* Cleanup
* Update API with function handlers
* Run clang-format
* Replace one-shot buffer with a direct queue.WriteBuffer using the buffer context
