ECSqlTestGenerator shows [object Object] in certain cases

[naveedkhan8067]

Check with the following query:

SELECT
  ECInstanceId,
  Model,
  dt,
  b,
  bin,
  DirectStr,
  DirectLong,
  DirectDouble,
  p2d,
  p3d
FROM
  aps.TestElement
LIMIT
  5

ECInstanceId	Model	dt	b	bin	DirectStr	DirectLong	DirectDouble	p2d	p3d
0x14	[object Object]	2017-01-01T00:00:00.000	true	1,2,3	str0	1000	0.1	[object Object]	[object Object]
0x15	[object Object]	2010-01-01T11:11:11.000	true	11,21,31,34,53,21,14,14,55,22	str1	1001	1.1	[**object Object]	[object Object**]
0x16	[object Object]	2017-01-01T00:00:00.000	true	1,2,3	str2	1002	2.1	[object Object]	[object Object]
0x17	[object Object]	2010-01-01T11:11:11.000	true	11,21,31,34,53,21,14,14,55,22	str3	1003	3.1	[object Object]	[object Object]
0x18	[object Object]	2017-01-01T00:00:00.000	true	1,2,3	str4	1004	4.1	[object Object]	[object Object]

https://github.com/iTwin/itwinjs-core/pull/8661