Add a test for multiple/single selection of StatefulInteractable and its various modes

[keveleigh]

Tests pass!

Release in same order	First hand select	Second hand select	First hand release	Second hand release
Single, triggerOnRelease	No click	Click	No click	Click
Single, !triggerOnRelease	Click	Click	No click	No click
Multiple, triggerOnRelease	No click	No click	No click	Click
Multiple, !triggerOnRelease	Click	No click	No click	No click

Release in reverse order	First hand select	Second hand select	Second hand release	First hand release
Single, triggerOnRelease	No click	Click	Click	No click
Single, !triggerOnRelease	Click	Click	No click	No click
Multiple, triggerOnRelease	No click	No click	No click	Click
Multiple, !triggerOnRelease	Click	No click	No click	No click