Where a loaded model came from. The ImportDialog records one of these against the model's id after a successful load so the ModelsPanel can surface "loaded via …" details.
Optional
Coordinate system applied at load, when the user overrode it.
ImportDataSet.id the user picked.
ImportDataSet.label — preserved as written when the load happened.
Filenames the user supplied, in ImportDataSet.files order.
ImportDataSet.files
Where a loaded model came from. The ImportDialog records one of these against the model's id after a successful load so the ModelsPanel can surface "loaded via …" details.