Show all upload errors on one page and add mapping option for rows when importing ideas via csv

Make it easier to correct errors when uploading CSVs.

Trying to upload a csv spreadsheet of ideas into Aha was one of the most painful experiences of my life and resulted in having to edit and upload the same spreadsheet about 7 times.

The first big improvement would be to show all errors on the screen for all columns at the same time (maybe with rows grouped into column sections) so you can resolve all errors at once. At the moment it only shows the first error for the first column so if you have errors in another column you don't realise until you try uploading the spreadsheet again.

A better improvement still would be the ability to map non-existent or incorrectly formatted fields upon upload.

E.g. if you had a spreadsheet of categories that hadn't been added in aha or had spelling mistakes in you could correct them on the upload with the option to assign them to an existing category to fix the spelling mistake or upload the new category without needing to add it to Aha first. I believe this is a function that already exists in other CSV uploaders like Mailchimp.