Removed ObjectStateIO, use identity functions in ObjectIO and use phetioState to opt in to state records, see https://github.com/phetsims/phet-io/issues/1100
Removed ObjectStateIO, use identity functions in ObjectIO and use phetioState to opt in to state records, see https://github.com/phetsims/phet-io/issues/1100

phetsims/scenery,phetsims/scenery,phetsims/scenery