CodingStyleTestCase: create real documents for test_DuplicateActions

no need to create temp objects because anyway the transaction is aborted
at the end of each test.
This solve a problem that some APIs behave differently on temp objects
and we don't really have use cases where we use actions on temp objects.

For reference, the case which fail is an action with a TALES condition
using a related accessor, the exact condition was:

    python: object.getAggregateRelated(portal_type="Implicit Item Movement") is not None