Allow sheets to have entirely empty rows

Problem/Motivation

There can be situations where rows are skipped entirely in the document. This should not result in an error and stop the import process.

This is only when the entire row is empty; this doesn't make sense if there is data in some cells but not in others. The main reason to have this to allow users to have templates, with dropdown etc for the first row.

Steps to reproduce

Simply skip a row in your document and try to import it, this will result in a validation error.

Proposed resolution

Always check if the entire row is empty first; if not start validating the cells.