fix handling same colName for existing colName, alias colName and group by colName

[jennifersp]

Fixed a case of table has col1 and it's used in the query for referencing this column, and using it for alias name for this column and using it for groupBy column. Example is SELECT col1, col1 AS col1 FROM tab1 GROUP BY col1 Follows MySql ONLY_FULL_GROUP_BY mode