Improve LazyCursorStateHintProvider unit tests

[jaredjj3]

They're returning incorrect data, see: #280 (comment)

[jaredjj3]

@rvilarl, this is next up in my queue unless something higher priority comes up.

[jaredjj3]

The problem is that the previous and current notes are swapped:

vexml/src/playback/lazycursorstatehintprovider.ts

Lines 33 to 36 in 1bfc4f7

	...this.getStartHints(currentElements, previousElements),
	...this.getStopHints(currentElements, previousElements),
	...this.getRetriggerHints(currentNotes, previousNotes),
	...this.getSustainHints(currentNotes, previousNotes),