Make the @export reference pop-up selector show children of scene instances by default.

[mattismoel]

Basically - would it be a good idea to show the children of scene instances by default, when selecting references for exported variables? Essentially, the whole philosophy of composition, tied with the philosophy of strict typing and reliable references kind of fall apart with the current way of doing things. Say we have some scene, that needs access to some specific SomeBehaviourComponent, that exists as a child of the scene instance SomeScene. The only way for the scene root to get access to the behaviour component is either through loose string reference with the likes of $SomeScene/SomeBehaviourComponent or an exported NodePath that by renaming the scene instances renders the reference useless. The other way is enabling "Editable Children", which seems totally overkill just to get a reference to the child node in another script.