Modernize test:

* Don't use hard cast to pointer in grid factory
* Pass transformation function using new interface
* Use `Dune::TestSuite` to get individual error messages for checks.

Fix failing test:

The test used hard coded values for the transformed coordinates.
These values are (now) incorrect and in fact permuted. Assuming
that this was once correct, the failure can be explained if
at one point the factory for AluGrid deciced to permute vertices
during grid construction. Then the hard coded values are no
longer OK. Instead of re-computing them manually the target
values are now derived from the transformation map which whould
work in any case and is less error prone.