Check current state of affairs re:native controls and LIVE content

[ismena]

Currently when playing LIVE content, we set the timeline duration to an arbitrary large value (2^32) to allow seeking. However, I saw that a LIVE stream played through hls.js supports a reasonable seeking/timeline experience with native controls. We should check if browsers made any progress on handling LIVE content and see if we might be able to provide a more decent experience with this.