Standardize the tandem hierarchy under "preferencesPanels"

[pixelzoom]

Over in phetsims/projectile-data-lab#30 (comment), these phetioID simplifications were made:

• preferencesPanels.simulationPreferencesPanel.simPreferences => preferencesPanels.simulationPreferencesPanel
• preferencesPanels.audioPreferencesPanel.audioPreferences => preferencesPanels.audioPreferencesPanel

... for 2 reasons:
(1) This approach of adding an intermediate tandem was inconsistent with the Studio tree structure for other Panels.
(2) 'simPreferences' and 'audioPreferences' were duplicated in sim code.

Going forward, sims should use this new convention. PDL, FEL, and the gas-properties suite have already been modified, since PhET-iO versions have not been published yet.

PDL was the only sim using "audioPreferences".

The following sims have NOT been published with PhET-iO, and have "simPreferences" in their phet-io-api.json file. They should be changed ASAP, before they need a migration processor:

• buoyancy
• circuit-construction-kit-ac

The following sims HAVE been published with PhET-iO, and have "simPreferences" in their phet-io-api.json file. They will required a (shared?) migration processor, and testing in the Migration wrapper. Publishing an MR for these sims is not recommended (or feasible?) because this is an API change.

• acid-base-solutions
• beers-law-lab
• build-an-atom
• center-and-variability
• circuit-construction-kit-dc
• circuit-construction-kit-dc-virtual-lab
• concentration
• density
• geometric-optics
• geometric-optics-basics
• greenhouse-effect
• keplers-laws
• molecule-polarity
• molecule-shapes

Recommended to do all of the above sims at once -- probably 3-5 hours. Doing them one at a time as they are republished will likely double the cost.

Assigning to @brent-phet to schedule and prioritize.

@arouinfar @kathy-phet @samreid @matthew-blackman FYI.

[zepumph]

We can make simPreferences bad text with lint after this work.