Duplicated members

[bstordrup]

In the PropertyModelBase class, a private readonly member JsonSchemaProperty _property is defined and populated in the constructor.

Also, in the derieved PropertyModel class, a private readopnly member JsonSchemaProperty _property is defined and populated in the constructor after passing it to the base constructor.

Is that not inefficient and memory waste? Would it not be a better approach to make the JsonSchemaProperty _property in PropertyModelBase be protected or expose it via a read-only protected property?