Add ability to wrap struct(or marked as public) fields as property

[RudenkoSergej]

We already have the "field_name" attribute for properties, which allows get/set methods use the public field of the impl class. But we don’t have a way to generate public fields for cases where it’s necessary to wrap the public interface wrap and impl classes to match.

It can be implement by a template class that:

• Arguments of the emplate - wrap class and field type.
• The constructor accepts a pointer to the wrap class pointer, and pointers on the Get and Set wrap class methods.
• Has overrided assignment and conversion operators for field type, thats will use Get and Set methods pointers.

Example how it works:
https://ideone.com/SsmKlg