ExtendableEvent.waitUntil API for Service Worker Environments

[n1ru4l]

I think we might need handling for the following within Yoga: https://developer.mozilla.org/en-US/docs/Web/API/ExtendableEvent/waitUntil

This is also used in https://developers.cloudflare.com/workers/runtime-apis/fetch-event/#methods
https://github.com/robertcepa/toucan-js/blob/41d9c6b4f20a1acbf6063114aec9124d856f673e/src/index.ts#L217-L234

The idea here is that the response can be returned/sent immediately, without first awaiting for additional task that does not NEED block the response such as error reporting.

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Related #1488

[ardatan]

This is no longer needed right @n1ru4l ?

[n1ru4l]

It is, I just did not make progress on the sentry plugin