Restart the app on errors and attempt to fix logging

[joao-paulo-parity]

• Crash and restart the app on errors so that we'll start receiving events again (bench-bot is not responding to commands sometimes #83 (comment))
  • This is not meant to be a permanent solution as the comment explains, but it's a stopgap fix until we have figured out Refactor the code #51
• Write to the systemd journal through systemd-cat instead of our custom monitor service so that we'll have better guarantees about errors appearing in the logs (Some errors are not reported properly in the logs #82)

close #83
close #82
close #70