improve difference display

For the "difference display" used for datasource import comparison, LM config comparison, and perhaps others, having to scroll through the entire file to find differences is super annoying as well as a source of errors since it is trivial to fly by an important change by accident.  Can we please have this changed to only show the changes and a few lines around the changes?  A toggle to turn that on or off would be perfect.

Thanks,
Mark