When parsing a text document treat /N and "null" as null values

When I bring a csv document from data lakes/other sources it does a fantastic job of parsing most initial csv issues - including promoting first row as headers and detecting types... what it doesn't do is parse out NULL values first.

What I'd like is for it to quickly do the NULL value checking and replace any likely null values prior to doing the data type detection - uppercase check against "" and "NULL" seem to be common.

This would solve the last of my initial changes to any data model straight from csv.