Detection of cyclic references for high level API

Summary

In previous versions conversion of containers including cyclic references using the high level API resulted in:

RecursionError: maximum recursion depth exceeded while calling a Python object  

That was fixed by adding a proper recursion detection to the function convert_to_python_object.

Focus

Have a look whether all functions involved in the conversion process use the dictionary for visited entities.

Test Environment

There is a unit test included.

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• I understand the intent of this MR
• All automated tests pass
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• Appropriate user and developer documentation (or not necessary)
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