refactor: optimize row handling in mssql extractor and transformer

internal/app/etl/extractors/mssql.go

@@ -89,14 +89,9 @@ func (mssqlEx *MssqlExtractor) Exec(
 	batchRows := make([]models.UnknownRowValues, 0, batchSize)
 	var rowsRead int64 = 0
 
-	rowValues := make([]any, len(columns))
-	scanArgs := make([]any, len(columns))
-	for i := range rowValues {
-		scanArgs[i] = &rowValues[i]
-	}
-
 	for rows.Next() {
-		if err := rows.Scan(scanArgs...); err != nil {
+		values, err := rows.Values()
+		if err != nil {
 			if len(batchRows) == 0 {
 				return rowsRead, err
 			}
@@ -110,7 +105,7 @@ func (mssqlEx *MssqlExtractor) Exec(
 		}
 		rowsRead++
 
-		batchRows = append(batchRows, rowValues)
+		batchRows = append(batchRows, values)
 		if len(batchRows) >= batchSize {
 			if err := flush(ctx, &partition, batchSize, batchRows, chBatchesOut); err != nil {
 				return rowsRead, err