DM-191: Measure and save aperture corrections in SFM

https://jira.lsstcorp.org/browse/DM-191
It's worth noting there that the ApCorrRegistry is not a part of configuration; it's the complete list of fields that could be aperture corrected if they were to be run.  So if something is present there and isn't in the configuration, that's not any kind of inconsistency.  It just means we chose not to run something.