Use more correct approach in list EVAL roundtrip
Use more correct approach in list EVAL roundtrip

The previous version of the test expected the same container to be
preserved for an itemized list despite roundtripping it through EVAL.
But this is incorrect because:

- we itemize two different lists despite both being empty
- why would method `item` always return same scalar container, whatever
  it wouldd mean in terms of comparing two containers
- and then we expect `EVAL` method to somehow preserve that container
  despite the string recevied from `raku` method does not provide us
  with any hints about the container details

So, the only correct approach for this test is to make sure that both
lists: directly itemized and roundtripped one, - are contained by the
same type of container.

In support of Raku/problem-solving#291

perl6/roast