Resolve "Convert all output to using that client for `cmd/config.go`"
General MR
Summary
Changes output handling in bbctl config
command to use the output client and adds formatting support for YAML, JSON, and TEXT config outputs.
Also adds unit tests for new config command format functionality.
Relevant logs/screenshots
Linked Issue
Upgrade Notices
Updates return type for MarshallHumanReadable interface definition from (string, error)
to ([]byte, error)
to match the return types for yaml and json.
Closes #140 (closed)