For every role file change, output the list of affected hosts

Corrective action from: https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/8528

For every role file we change we should list what hosts will be affected and add it to the MR for review, this should be as easy as a pipeline step that does a knife search -i and post the output

Also - is there a way to clearly show if a prod host is affected? Don't want to fail the pipeline, but explore what we can do here?