Shape.getOffsetShape fails when Shape is very small

[pixelzoom]

This was discovered in phetsims/vector-addition#261, see history there. (A workaround was applied to move forward for that issue.) The Shape in that case was the ArrowShape associated with an ArrowNode, and the ArrowNode's dimensions were 1.5157520574185608e-15 x 12.

[ariel-phet]

@jonathanolson since this is no longer a blocking issue, it is not super high priority, however, while it is fresh in your mind, might be worth handling soon. Marking medium priority