Add support for workers (OffscreenCanvas)

[tobiu]

related to:
chartjs/Chart.js#11891

Dedicated workers do support request / cancelAnimationFrame. SharedWorkers however sadly do not.

https://github.com/Robloche/chartjs-plugin-streaming/blob/master/src/helpers/helpers.streaming.js#L28C1-L33C6

const cancelAnimFrame = (function() {
  if (typeof window === 'undefined') {
    return noop;
  }
  return window.cancelAnimationFrame;
}());

needs a change.

bigger picture:
chartjs/Chart.js#11890

=> especially streaming data is a perfect use case for OffscreenCanvas.

best regards,
tobias