request_timeout not used in HttpFetcher

Problem/Motivation

No matter how high I set the request_timeout, I am always met with "...cURL error 28: Operation timed out after 30001 milliseconds with 0 bytes received..."

Looks to be that `$options = [RequestOptions::SINK => $sink];` does not add the timeout for the call.

Using a custom fetcher, I have resolved for now by updating to

$options = [
  RequestOptions::SINK => $sink,
  'timeout' => $this->configuration['request_timeout'],
];