This ticket is to investigate whether whether we perform unnecessary writes when doing updates with a column index, and to fix such cases.

Case 1: The column index has a columnstoreProjection, and a field that does not fall into the projection is modified. This should not require us to write to the index at all.

Case 2: Only one (or a handful) of paths are modified in an update. The unmodified paths should not have to be re-written.