Handle skip intro/credit

[StaehliJ]

As an integrator, I can present a skip intro or skip credit button to the user.

To handle skip intro/credit, we may create a custom event that is triggered when the player reaches the time interval.

Acceptance criteria

• An API to query timed event at a position is available.
• Integrator is notified when time event enter/exit during normal player playback.
• Demo shows a skip intro/credit.