Convert dictionary definition to use new PlayButton view

This removes the custom play button from definition and replaces it with the new core ```PlayButton``.

Depends on internal PR. Make sure that's merged first.

@jdorweiler @russellholt @jagtalon @sdougbrown
```after``` refers to location on the DOM where the view is added. The base view class takes either ```appendTo```, ```before``` or ```after``` to specify where to insert the view on the DOM.