RuntimeInvocation: added basic support for interfaces

Interfaces must decend from IInvokable or be compiled with {$M+}
alternatively {$TYPEINFO ON} in order for the necessary RTTI to be
available.
Functional: Map function, interface wrapping

Functional.Map applies a transformation function to each element in the
source enumerator before returning the transformed element.

Wrapper can now handle interfaces which contain RTTI, ie either descend
from IInvokable or is otherwise compiled with RTTI ($M+ for example).
This allows wrapping of Spring4D collections etc.