[CMSP-579] Pass more info to pantheon_wp_rest_api_surrogate_keys filter

[TrilipuT]

Hi
I tried to add surrogate keys to my custom REST endpoint but found that it's a bit tricky to define what requests you are on right now. I used $_SERVER['REQUEST_URI'] to check what uri is being requested.
I think it will be easier if you can pass more parameters from original filter - that will help to operate data more flexible.
$response, $server, $request or whatewer available there.

[jazzsequence]

Thanks for the feedback. Tracking this internally as CMSP-579. We'll need to figure out where to prioritize this and add it into our development schedule, but it's a valid point and would be a good add.