Send pause when no surface is connected to player

[StaehliJ]

Pull request

Description

The goal of this PR is to update ComScoreTracker to handle background state correctly. We have to send a pause event when the video is not visible by the user and send a play event with the new position when video is visible again.

Solution

We assume that a player with no surface size is a player with no surface attached to it and so actually not visible by the user.

Changes made

• Improve background / foreground video tracking for ComScore.

Checklist

• Your branch has been rebased onto the main branch.
• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).
• All pull request status checks pass.