HV-877 Supporting type use constraints on type arguments

This applies to `PropertyMetaData`. After your feedback, I'll continue the work on parameters and return values and I'll extend `ParameterMetaData` and `ReturnValueMetaData`.
> Ah, good to think about the BV meta-model as well. I don't think we really need it right now, though. 

I thought I have everything in place for BV1.2. Do you prefer to remove this?

> I don't think a user could access it in any way via the BV API?

Can't the user access it through `TypeArgumentMetaData#asDescriptor` ?