Oec 374, Update primary OEC script to pad CCNs and add columns

The primary OEC script lives within CalCentral code and generates CSV files. A secondary script - owned by Ops - then processes those CSVs. We plan to retire the secondary script and consolidate logic in primary.
Course control nums that lack their 5-digit padding have bitten us in the past. Can you add a test asserting the 5-digit-ness of CCNs that would otherwise be 4? (e.g. test asserting that CCN "01234" comes out as such and not as "1234".