convert TimeSpeed to new enumeration pattern, https://github.com/phetsims/scenery-pNeuronClockModelAdapter.jshet/issues/736
convert TimeSpeed to new enumeration pattern, https://github.com/phetsims/scenery-pNeuronClockModelAdapter.jshet/issues/736

phetsims/energy-forms-and-changes,phetsims/energy-forms-and-changes,phetsims/energy-forms-and-changes