Upgrade checker

[alyblenkin]

Run existing submissions through engine headless, compare the resulting submission with the original

[latin-panda]

@alyblenkin, is this about comparing existing submissions sent via Enketo with those from Web Forms?

[alyblenkin]

@latin-panda yes, this is the idea we spoke about towards the end of our call. Maybe we actually want to create two stories, one for our own testing, and one that allows users to compare the submissions. @lognaturel what do you think?

[lognaturel]

I think we should focus on building something that can be run on existing Central servers' submissions first and then evaluate whether there would be value to providing something user-facing. I think there are enough existing submissions that we'd likely catch any existing discrepancies. I also suspect there will be a fair number to triage.