The Annotation importer plug-in should provide some example values from the file when mapping columns to annotations

[Nicklas Nordborg]

The first step in the importer can use the "Test with file" functionality which allow the user to see the actual data in the file which makes the mapping a lot easier.

In the second step where columns are matched to annotations this information is no longer available. It would be nice if a few data lines from the file could be displayed to help the user when the automatic matching doesn't find the correct annotations.

[Nicklas Nordborg]

In 8317:

Fixes #2338: The Annotation importer plug-in should provide some example values from the file when mapping columns to annotations