Expose `ended` property

react-player provides onEnded that is useful for doing things when the video is done playing. DashPlayer should expose an ended property that is True when the video has finished playing. I can do a workaround by comparing the currentTime to the duration but in my opinion it's not the best workaround because the callback fires every n milliseconds when using the currentTime as an Input, whereas it could just fire once if ended was exposed.

Beginne damit, die Komponente DashPlayer und ihre React-Player-Integration nachzuverfolgen, um festzustellen, wo die offengelegten Wiedergabeeigenschaften definiert sind. Bestätige, dass eine Eigenschaft ended true meldet, wenn das Video beendet ist, und dass dieses Verhalten durch die vorhandene Validierung oder Tests des Repositorys abgedeckt ist.