Improve handling of complex inheritance that includes enumeration

[DennisAlund]

There are complex relationships where a class both inherits from enumeration and other classes at the same time. The best way to handle this for now is to just represent the enumeration as an String option type

See for example https://schema.org/CreditCard that has the inheritance structure

Thing > Intangible > Service > FinancialProduct > LoanOrCredit > CreditCard
Thing > Intangible > Service > FinancialProduct > PaymentCard > CreditCard
Thing > Intangible > Enumeration > PaymentMethod > PaymentCard > CreditCard

Since the enumerations in the end are resolved to strings, the current implementation seems impossible to do any reasonable implementation apart from changing the enumeration path of inheritance into simply changing it into a String.