Preprocessing tab section missing in report

[clabornd]

After selecting all columns to be computed in the preprocessing tab, the section of 'added variables' does not show up in the downloaded report.

This is because we reference the columns in revals$uploaded_data$e_meta and compare them to the e_meta columns in the final data. Unfortunately revals$uploaded_data is a misnomer, as it refers to data up to just before the filter tab, so it includes columns added in the preprocessing tab, and so we think no columns were added and the section doesn't show up. We need to have a separate uploaded data or keep track of the original columns somewhere.