V4 worker pipeline / worker pipeline handler

[nico-martin]

Add Web Worker Pipeline Support

This PR reminded me that other libraries offer a fairly simple way to interact with web workers.
So this PR adds a worker_pipeline that can be used to replace the pipeline and a worker_pipeline_handler that handles the web worker requests.

Usage

Main Thread:

import { worker_pipeline } from '@huggingface/transformers';

const worker = new Worker('worker.js', { type: 'module' });

const pipe = await worker_pipeline(
  worker,
  'background-removal',
  'Xenova/modnet',
  {
    device: 'webgpu',
    progress_callback: (e) => {
      console.log('Loading:', e.file);
    },
  }
);

const result = await pipe(image);

Worker Thread (worker.js):

import { worker_pipeline_handler } from '@huggingface/transformers';

const handler = worker_pipeline_handler();
self.onmessage = handler.onmessage;

[HuggingFaceDocBuilderDev]

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[nico-martin]

closed in favor of #1516