Add RTTI support (dynamic casts)

[fsahmad]

Currently ACT does not make it possible to perform dynamic downcasts on binding objects, it is left up to the API implementer to provide the necessary runtime type information, and maintain it.

As ACT already has all the necessary information about the type hierarchy, it would be very useful to have ACT generate everything that's needed to enable the following:

using namespace MyComponent;
void MyFunction(PBase anyObj) {

    if (auto wire = mycomponent_cast<PWire>(anyObj)) {
      DoSomethingWithWire(wire);
    }
}