Alter data imports from normalizer services

[jsstevenson]

Some scattered thoughts I've had

• previously we only imported normalizer terms that went into groups. Now I think that maybe we should be treating these sources like the other importer sources, both from a module perspective and with how data import happens all at once. This would require a way for the normalizers to ship some kind of "view all records" feature but that might not be a bad idea anyway.
• it would be good to break groupers a bit more into new modules otherwise. I think the groupers modules are covering too many concerns at once by themselves and it's getting harder to maintain.