Add logging

• Poetry add pyyaml
• Add logging.yaml file (Eg. https://gitlab.cern.ch/push-notifications/notifications-routing/-/blob/03e04288e3dcd6cad9cf08ba129a8300e4c20eb0/logging.yaml)
• Add configure_logging method (Eg. https://gitlab.cern.ch/push-notifications/notifications-routing/-/blob/03e04288e3dcd6cad9cf08ba129a8300e4c20eb0/notifications_routing/app.py#L44)
• Add some logs (Eg: https://gitlab.cern.ch/push-notifications/notifications-routing/-/blob/f636a3d24ea6089472b569a4ea5ff14649592333/notifications_routing/router.py#L42)