Provide an easy way to override the status code dynamically

[VincentLanglet]

Description
Maybe this already exists and I don't find it but I'd have a POST route I'd like to return a respond with either a 200 or a 202 status code.
Currently this does not seems to be supported since the Operation::getStatusCode is a single integer.

Does it exists @soyuka ? Are you ok with such feature ?
What do you recommend for this ?

I'm not sure but if the status is coming for here

core/src/State/Processor/RespondProcessor.php

Line 64 in 61c6dee

$status = $this->getStatus($request, $operation, $context);

It could be easy to change here

core/src/State/Util/HttpResponseStatusTrait.php

Line 40 in 61c6dee

$status = $operation->getStatus();

into

$status = $request->attributes('_api_response_status', $operation->getStatus());

Example

class MyProcessor
{
      public function process()
      {
           if ($count > 25) {
                      $request->attributes->set('_api_response_status', 202);
                      $dispatcher->publish(...);
           } else {
                      // default status will be 200
                      $service->execute(...);
           }

           return $output;
      }
}