Setting playbackRange does not update visual selection

[Danielku15]

Your environment

• Version used: (master branch)
• Platform used: JavaScript
• Rendering engine used: SVG
• Browser Name and Version: all
• Operating System and version (desktop or mobile): all

Expected Results

When setting the playback range via API call, the visual selection indicators should update automatically.

Observed Results

Only the player is affected by the change, but the selection indicators do not update.

Steps to Reproduce (for bugs)

1. Call api.playbackRange = {startTick: 300, endTick: 800 }
2. Notice the range not updating.

Possible Solution

We would need to lookup first the start&end beat using the given ticks from the tick cache. Then we can just update the selections internally.