The shuffle group on NIE should include the target step name and mode

We need to include information about the step name being targetted and how it is targetted in the shuffle group

Start by locating the Java code that builds or reports the shuffle group in the NIE flow. Trace how the target step and targeting mode are represented, then check existing tests around shuffle-group output. Done means the shuffle group includes both the targeted step name and how it is targeted.

Written by the indexing model from the issue text.