Include default video scrubber bar and buttons with VideoEditor

The `VideoEditor` is convenient for displaying videos within a TraitsUI view; however, in most instances when one wants to play a video, they will generally expect to be able to control the video via:

- A scrubber bar that shows the current video position, allows the user to seek to a different time in the video, and displays start and end timestamps
- A play/pause button

Currently, one needs to implement these items manually whenever the `VideoEditor` is used. It would be nice if a bar below the video with this functionality could be provided by default (with potentially the option to hide for those situations where it is not desired).