QUDT Quantity Value Integration

[ThHanke]

For using QUDT value translation between units, I would like to have QUDT Quantity Value Integrated into Value Specification.
QUDT Quantity Value is rather simple.
Maybe we can have it as subclass to ValueSpecification. if so we might do the same with qudt:value and qudt:unit which are the object properties relateing fro it same as hasValue and hasUnit.