Make job and runner tags available in admission request

We got feedback from an early admission controller user that it would be valuable to have at least the defined job tags and potentially also the configured runner tags available in the job admission request in the runner controller.

At the moment this is not straight up possible because the existing job response definition in Rails (https://gitlab.com/gitlab-org/gitlab/-/blob/admit-job-runner-tags/lib/api/entities/ci/job_request/response.rb) does not contain it. That is, the runner never receives that information with a job.

To make this work we need to define our own job request response entity that we use in the internal API endpoint in the job router and return that information. We then need can optionally strip that data when sending it to the runner (it's likely okay to send it though, we need to double check).