message: Fix for struct output in shell test
diff: @@ -66,8 +66,8 @@ SELECT SUM(i) FROM a;
  # nested types
  test('select LIST_VALUE(1, 2);', out='[1, 2]')
  -test("select STRUCT_PACK(x := 3, y := 3);", out='<x: 3, y: 3>')
  -test("select STRUCT_PACK(x := 3, y := LIST_VALUE(1, 2));", out='<x: 3, y: [1, 2]>')
  +test("select STRUCT_PACK(x := 3, y := 3);", out="{'x': 3, 'y': 3}")
  +test("select STRUCT_PACK(x := 3, y := LIST_VALUE(1, 2));", out="{'x': 3, 'y': [1, 2]}")
  test('''
  CREATE TABLE a (i STRING);
  