Give MigrateMapSaveEvent the migrate $row object

Problem/Motivation

The Migrate Devel module can output on the CLI the data of the row about to be saved, or after it has been saved.

However, for a skipped row, there is no output. This is a case where a developer might particularly want to see what the data in the row is!

This feature can't be added to Migrate Devel module (see ✨ debug output for skipped rows Postponed ) because the MigrateMapSaveEvent doesn't have the migration $row object.

Steps to reproduce

Proposed resolution

Add the $row object to the event.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet