Auto-map fields in the interactive mapper where appropriate

[jedateach]

Check the headings of a CSV, and automatically set the dropdown selections to any headings that match existing options.

For example, if a CSV has a Title heading/column, and and the mappable fields list contains Title, then the mapping dropdown for that column should automatically default to the Title selection.

A further improvement would be to do some kind of fuzzy matching, where the system guesses which fields map to which.