#1514 Enhance submission review pages to look for unchanged submitted values

[Ahasuerus]

Normally, any values that haven't been changed in the submission form do not get included in the body of the submission. However, it's possible for duplicate submissions or submissions created out of order to produce a scenario where the "current record" value and the "proposed changes" value are the same for one or more fields. When this happens, we want the software to behave as follows:

1. Both the "current record" table cell and the "proposed changes" table cell should have a green background; currently the "current record" cell has a red background.
2. The "Warnings" column should notify the reviewer that the two values are identical.