Explore handling auth token parse error more cleanly

[eaddingtonwhite]

Currently if someone copy and pastes an auth token incorrectly into momento configure they get the following error

 [2022-04-11T21:27:40Z ERROR momento] panicked at 'called `Result::unwrap()` on an `Err` value: ClientSdkError("Failed to parse Auth Token")', client-sdk-rust/src/utils.rs:34:36

Can we explore if we can handle this more cleanly and maybe prompt user to double check they copied and pasted their token properly during configure command.