Add onErrorShell Callback (#23247)

This indicates that an error has happened before the shell completed and
there's no point in emitting the result of this stream.

This is not quite the same as other fatal errors that can happen even
after streaming as started.

It's also not quite the same as onError before onCompleteShell because
onError can be called for an error inside a Suspense boundary before the
shell completes.

Implement shell error handling in Node SSR fixtures

Instead of hanging indefinitely.

Update Browser Fixture

Expose onErrorShell to the Node build

This API is not Promisified so it's just a separate callback instead.

Promisify the Browser Fizz API

It's now a Promise of a readable stream. The Promise resolves when the
shell completes. If the shell errors, the Promise is rejected.