Write an RFD for updating Hipcheck's output formats.

[alilleybrinker]

Today Hipcheck supports two output formats, a JSON format and a human-readable format. Unfortunately, because it was added later and haphazardly, the JSON format does not include the full detail included in the human-readable output (technically, all the information is there, but without any of the helpful explanatory text included in the human-readable output, so it's usable only by the few Hipcheck experts around).

We want to bring these two into alignment, but we'll also need to grapple with what Hipcheck output should look like in the face of the new plugin system. This means assessing the output is at least in part dependent on the other RFDs around the redesign of Hipcheck's core architecture (#6, #10, #11, #12).

Once those are resolved, but likely before we've completed the implementation of the architecture update, we should write an RFD for Hipcheck's new outputs, addressing both what ought to be added / removed / changed to reflect the new architecture better, and how to make sure the two output formats are consistent with each other.

Relatedly, we'd had prior conversations with the folks involved in the Heimdall project about either adopting the Heimdall Data Format for Hipcheck's output, or collaborating to produce an adapter which could take Hipcheck's output and convert it into the Heimdall Data Format. This choice hasn't yet been resolved, and ideally the RFD would answer it one way or the other.