Implement Loguru for better logging

[smoia]

So far we're adopting basic logging - 95% of the time that's ok, but for instance the logs are not catching errors, which is annoying for bugfixes.

Loguru might offer a solution, at a very small dependency cost - especially if not on Windows (otherwise two small dependencies more to deal with their terminal).

I think it'd be neat to implement it!

[maestroque]

Should this be closed?