fix: removing super.ready method and triggering PLAYBACK_READY event
fix: removing super.ready method and triggering PLAYBACK_READY event

There is a bug when trying to play the same video again. The "super.ready()" method uses an internal flag (_isReadyState) that is never cleaned.
In this commit we're managing ready state only in DashShakaPlayback and totally skipping the HTML5VideoPlayback ready state control.


clappr/dash-shaka-playback,clappr/dash-shaka-playback,clappr/dash-shaka-playback