transform does not work with DateTime64

[darkleaf]

select transform('a', ['a', 'b'], [toDateTime64(1,3), toDateTime64(2,3)], toDateTime64(0,3));

Received exception from server (version 21.11.5):
Code: 44. DB::Exception: Received from localhost:9000. DB::Exception: Illegal column String of elements of array of second argument of function transform: While processing transform('a', ['a', 'b'], [toDateTime64(1, 3), toDateTime64(2, 3)], toDateTime64(0, 3)). (ILLEGAL_COLUMN)

select transform('a', ['a', 'b'], [toDateTime(1), toDateTime(2)], toDateTime(0));

┌─transform('a', ['a', 'b'], array(toDateTime(1), toDateTime(2)), toDateTime(0))─┐
│                                                            1970-01-01 00:00:01 │
└────────────────────────────────────────────────────────────────────────────────┘

I expect it returns toDateTime64(1,3) like for DateTime but it fails.

Clickhouse version is 21.11.5.33.

[vdimir]

Need to support this type like in #31839