use Heap Types in PySide and Shiboken

PySide and Shiboken did never make use of the Python heap types.

To be able to support the stable API, the use of heap types becomes mandatory because the PEP 384 (limited API) replaces the type structures of all types by API calls which create heap types.

At this point we are really stuck when we want to build wheels that work for multiple Python 3 versions, so unless this task is solved, it is a blocker.

But I am optimistic ...