Add an E2 core for adv dupe2

[JohnWeak1]

it would be nice if there would be an e2 core for adv dupe2

where you could have functions like :
runOnAdvDupe(n)
r = LastDupeEntities()
r = LastDupeConstraints()
e = LastDupeOwner()
and more if that's possible.

[thegrb93]

Will label wontfix until someone decides they want to do the work.

[Vurv78]

Easy fix now with the events system, best time for anyone to do it