Core/Instance: Implement Dynamic Difficulty Map

this solves issue where player only should get one instance id for 10man and 25man

1part for #2374
the idea was when a map is "IsDynamicDifficultyMap" then just create a 10man or a 25man instance bind.
i need this line because the bind is always "normal mode" so it is needed that player can also have a heroic map