dev: mirror grafana script in prometheus script

Created by: bobheadxi

follow-up to #11533

• align Prometheus script with Grafana script
  • remove prometheus custom container shutdown (this also removes the "prometheus not found" message when stopping ./dev/start I've been seeing)
  • reorders related steps so that they're roughly in the same order as the Grafana script
  • moves prometheus logs to a similar directory
• fix grafana script on mac - it seems like docker was being confused by the empty lines? fiddled around with it until it worked