redesign PhET-iO API

[zepumph]

This sim was last instrumented for PhET-iO with the "instrument everything" approach. It should be updated.

In addition to the general updates. I am mainly creating this issue now because of discussion with the Accessibility team. @emily-phet, @jessegreenberg and I today discussed the expansive difficulties in handling the intersection of auditory description and phet-io. One potential baby step that we came up with was in understanding the full feature set of the sim (including what can be done with phet-io) before tackling auditory descriptions. We thought it could help the description design process to have this meeting before too long. This way it didn't feel like auditory descriptions were implemented, and then needed to take on a fully different shape after a new (phet-io) feature set was exposed.

That said I don't know the MAL priority for phet-io, and I'm not sure when we will be able to get to this.

Tagging @Matthew-phet also so that he can be looped into how phet-io features could impact the design of auditory descriptions. This is all at the beginning stages, and I'm unsure how this will work in practice. That said I'm excited to explore (even at a rudimentary level) the steps necessary to supporting both of these in the same simulation.

Next steps for this issue would be for me to go through the sim and clean up a bit, that will also help me understand the current feature set.