CLEO should have better error handling and logging

[kKdH]

To improve the user experience of CLEO (mostly in failure situations) a '--verbose' flag could provide more information to a user and help to solve the problem faster.

At the moment CLEO is not showing logs but it might be helpful to see log statements when using CLEO. A viable option is printing the logs on stderr instead of stdout. By default only error and warning logs may be shown. The verbose flag may be used to increase the log level to show debug logs as well.

• [ ] JSON output can still be used by jq for automation
• [ ] Errors are shown to the user
• [x] Verbose flag increases the log level to DEBUG

[mbfm]

This probably makes sense to use for the verbosity flag: https://crates.io/crates/clap-verbosity-flag