Add reference contents of embodiment AtomSpace after perceiving TestScene3 ...

...to help in planning both AtomSpace visualization and learning algorithms, and to help in debugging the way we are representing the world from the perception code using this reference example of an actual world definition.

Associated with this new level definition:
https://github.com/opencog/unity3d-opencog-game/commit/adc2d56bdadc336b576fbbfced25d3ef6e4ee6a8