Standardize column names in REDCap

[lwjohnst86]

Rather than us make changes in the data package, it would be better if the source REDCap fields had a standardized naming structure. This should be documented here as a "naming" page.

E.g. any keys should end in _id, dates should have either _at or date_ or something, admin only fields should be prepended with admin_ or similar.

[K-Beicher]

Unfortunately this can't be done in REDCap once it is in production. I'll make an issue about setting up a mapping doc.