sublist: Add same digits different numbers test
sublist: Add same digits different numbers test

Complies with:
* https://github.com/exercism/x-common/pull/438
* https://github.com/exercism/x-common/issues/432

I would it find it unlikely that someone will take this approach in this
language, but that's OK, we can add it to be sure.

exercism/xhaskell