Show child/leaf entities of the selected entity in the Entity Graph diagram

[fmihaly]

It would be useful alternatively to be able to show the underlying entities (child classes/properties) of the selected class or property, in opposite of the super classes/property hierarchy in the "Entity Graph" diagram.

[damienriehlfc]

Similarly, it would be helpful to be able to show/hide an entity's Siblings. (That is, entities that share the same Parent.)