fix: beside skipping empty rows, empty cells should be skipped as wel…

…l; avoid unnecessary empty cells in final sheet covering longer cells left of them

xmlWorksheet.go

@@ -717,7 +717,7 @@ func (worksheet *xlsxWorksheet) makeXlsxRowFromRow(row *Row, styles *xlsxStyleSh
 		xRow.C = append(xRow.C, xC)
 
 		return nil
-	})
+	}, SkipEmptyCells)
 
 	return xRow, err
 }