TimeSpeedProperty valid values don't match Time Speed radio buttons

[Denz1994]

Discovered during phetsims/scenery-phet#607:

In the studio view of WOAS, searching for "TimeSpeedProperty" shows Valid Values: Fast, Normal, Slow. However, the radio buttons are limited to only "Normal" and "Slow". Selecting the "Fast" option in the studio view will deselect both radio buttons in the sim view and doesn't seem to change the sim speed.

I would expect the "Fast" option to not be present in the studio view as a valid value. Assigning responsible dev to investigate.

See this comment under the "Studio" content for more context and a potential solution.