`http_api_curl` hook no longer available for adding custom cURL options

[ChaseWiseman]

Now that 4.6 has implemented the new Requests library, the http_api_curl hook is no longer used when building cURL requests, and I see that its removal was mentioned and expected in #33055. That said, as far as I can tell there is no longer an easy way to intercept before curl_exec is run. There are a lot of posts and projects that suggest this old hook for setting options like CURLOPT_SSLVERSION and the like, so I think it'd be beneficial to maintain this ability.

The only way around it I've found is to skip wp_remote_request() and roll your own Requests::request() call and pass it the $options['hooks'] after registering your own callback for the curl.before_send hook.

Would it make sense to add a filter to $options before calling Requests::request() so folks can register their own callbacks, similar to this https://core.trac.wordpress.org/browser/trunk/src/wp-includes/class-http.php#L311? Or perhaps there is another way of going about it that I'm missing, and I'm happy to work up a patch if someone more familiar with the library can suggest a good place for this.

Thanks!