deleteRelation parametrizable

Merge Request

🥅 Description

The method deleteRelation in the GenericDao is used only for deleting relations between DataObjects and can be applied only if both entitities are of the same type. To enable further use, this function is made generic by passing also the types of the two entities to it.

📷 Screenshot

📓 Checklist

• The code compiles without any warnings.
• I followed the code review checklist.
• The documentation has been added/updated.

🔗 Related Issues

• Related #
• Closes #566 (closed)