Update CLI test validation

[dbarbuzzi]

This PR updates the validation of CLI command tests. The checks for things like "error" or "failure" in the command output are problematic because they can simply be part of a log message/warning that ultimately does not impact the success of the command being run. For more involved validation, output messages/files should be verified. Recently, some output seemingly from transformers has, for example, included the word “error” which caused test failures.

Additionally, this fleshes out some validation for one of the commands that was previously commented out.