Assigning a column to a catalog and its margin

In working to make sure that catalog methods also apply to the margin catalog, assign seems like a harder case. If a user is assigning a series that is partitioned to fit the catalog's partitions, then to apply the same column to the margin we would need to do some sort of join or map/reduce to rearrange the column to fit with the margin's partitions. I think this would be fairly inefficient and break a lot of the extremely parallel operations we have.

Alternatively, we could leave this to the user, and accept the catalog and margin columns separately to assign, but this then leaves the work on the user.