Better handle errors encountered when running anoma binaries

[james-chf]

Currently in the anoma CLIs we sometimes handle errors by calling eprintln! with a human-friendly error message, then exiting the process with status code 1, other times we just attempt an .unwrap() which panics and displays an output more helpful to developers.

We could consolidate how we're handling errors:

• start returning Result<()> instead of safe exiting inside our functions; e.g. use .await? rather than await.unwrap() to return errors when they happen rather than panicking
• change existing eprintln! calls to returning a Result<()>
• at the top level, catch returned Err(error)s and always both eprintln! the Display trait output for users and log (i.e. tracing::error!) the Debug output for developers, as currently we may only get one or the other

This could be done nearer Namada release as part of polishing up if there is time