AccessionUploader: crop

Genesys currently uses accession.cropName to determine and set accession.crop. During uploading there is now no possibility to provide the crop and prevent automatic assignment.

This issue is to add support for crop string to AccessionUploader. Acceptable values is any of the Crop#shortNames.

If "crop" exists in incoming JSON then accession.crop should be set to the Crop by shortName (if exact match is found). If match is not found or "crop" is not provided in JSON then the current logic is used.