Fixes #4849 - Hammer fails silently when no cache is generated

This is the foreman part. I'm trying to catch and handle the exception with the exception handler. It is then re-raised for hammer to behave consistently. I was thinking about raising `HammerCLI::ModuleLoadException` instead, to not have the same error in the logs twice, any comments?

The core changes - https://github.com/theforeman/hammer-cli/pull/100