Remove columns that have NA in a row
remove_na_columns_in_row.RdThis is a helper function for set_user_file_header. Before set_header_row can be called, we need to make sure there are no NAs in the row because we should not have NAs as column headers. At this point we know what the header row should be so we can simply remove columns at this point. This helps resolve bugs - if he user has a random character in a row, it will create a new column. This potentially could be addressed during preprocessing but the advantage of handling this in set_user_file_header is that we have have the columns that we want and we can confidently remove anything else.