Playlab go to xy

Necessary for animation in MSM (particularly quadratic motion and nonlinear acceleration). I don’t expect this
block to be used directly by students (at least not in any of our
current courses).
I think best approach might be to make a new string "moveSpriteNTo": "move actor {spriteIndex} to". Also, is there a reason we want a different title if spriteCount is 1, or is this just code that was copy/pasted from elsewhere.