[Refactor] We do use different logger

[6543]

• github.com/rs/zerolog
• github.com/sirupsen/logrus

I propose to:

• use only on logger (Move entirely to zerolog #426)
• clean up logging (Replace debug with log-level flag #440)
• make logging level change on demand
  • via Enviroment (Replace debug with log-level flag #440)
  • via API request (admin only)) (Add log level API #444)
• introduce structural logging -> we are able to now with zerolog but that can be extended later :)
• more logging (More logging and refactor #457)

[jolheiser]

I've only used it a few times, but I'll +1 zerolog.

[jolheiser]

Once #426 is merged I would like to tackle changing the log level on demand.

[6543]

@jolheiser thanks 🎉 !