Should RectangularStickyToggleButton use the 'pushButton' SoundPlayer?

[jessegreenberg]

While working on #796 we noticed that RectangularStickyToggleButton does not use the same SoundPlayer that RoundStickyToggleButton uses. We were wondering if it should?

I suspect we can copy the pattern used in RoundStickyToggleButton and I am happy to do it, but I wanted to run it by @jbphet first to make sure.

[jbphet]

Makes sense to me that they should be consistent. I'd so go for it @jessegreenberg. And thanks.

[jessegreenberg]

Great, thanks! I added the sound player, and also a required tandem so RectangularStickyToggleButton and RoundStickyToggleButton options are the same. Closing.