Support chaining multiple result sets.

tests/queries/t_can_contain_multiple_result_sets.nim

@@ -0,0 +1,42 @@
+# vim: set et sta sw=4 ts=4 :
+
+discard """
+output: "Jenny|Lenny\nLenny\nJenny\n"
+"""
+
+import kuzu
+
+let db = newKuzuDatabase()
+let conn = db.connect
+
+var q = conn.query """
+CREATE NODE TABLE User(
+    id SERIAL PRIMARY KEY,
+    name STRING
+);
+
+CREATE REL TABLE FOLLOWS(
+   From User To User
+);
+
+MERGE (a:User {name: "Lenny"})-[f:Follows]->(b:User {name: "Jenny"});
+"""
+
+q = conn.query( "MATCH (u:User) RETURN *" )
+
+assert typeOf( q ) is KuzuQueryResult
+assert q.hasNextSet == false
+
+q = conn.query """
+    MATCH (a:User)<-[f:Follows]-(b:User) RETURN a.name, b.name;
+    MATCH (u:User) RETURN u.name;
+"""
+
+assert typeOf( q ) is KuzuQueryResult
+assert q.hasNextSet == true
+
+echo q.getNext
+for query_result in q.sets:
+    for row in query_result.items:
+        echo row
+