throw exception when dweller tries to stand on impossible side (blocked by a cube)
reset position dweller when standing on a side

 - set dweller’s initial position from Up to Back side of the core cube
add initial rotation constants for each side
a side set its rotation itself
(trivial) extract TweenCompleteParams variable
apply tween complete callback to both of the tweens (move path and rotation)
change test tween (from “Back=>Up” tween to “Down=>Back” tween)