text: Title: Let query engine determine free port
  Body: ## Problem
  
  <!-- A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] -->
  
  There is a race condition between when we choose a port to run the query engine on & another process using that port while the query engine is starting up.
  
  ## Suggested solution
  
  <!-- A clear and concise description of what you want to happen. -->
  
  Pass in `--port=0` and parse the log message.
  
  We don't currently parse any logs from the query engine so getting that setup will be the most challenging part here.