Fix: handling the select distinct keyword

Author: taewhi

traindb-core/src/main/codegen/templates/Parser.jj

@@ -1314,13 +1314,11 @@ SqlSelect SqlSelect() :
  (
  <STREAM> {
  keywords.add(SqlSelectKeyword.STREAM.symbol(getPos()));
- traindbKeywords.add(SqlSelectKeyword.STREAM.symbol(getPos()));
  }
  )?
  (
  keyword = AllOrDistinct() {
  keywords.add(keyword);
- traindbKeywords.add(keyword);
  }
  )?
  {

traindb-core/src/test/resources/sql/basic.iq

@@ -74,4 +74,25 @@ WHERE a.product_id = b.product_id;
 +---------+
 (1 row)
 
-!ok
+!ok
+
+SELECT DISTINCT reordered FROM instacart_small.order_products ORDER BY reordered;
++-----------+
+| reordered |
++-----------+
+| 0 |
+| 1 |
++-----------+
+(2 rows)
+
+!ok
+
+SELECT count(DISTINCT reordered) as distinct_cnt FROM instacart_small.order_products;
++--------------+
+| distinct_cnt |
++--------------+
+| 2 |
++--------------+
+(1 row)
+
+!ok