Adding `exclude_missing_ball_frames` for all tracking data providers

[UnravelSports]

See the discussion in #523. Basically, SecondSpectrum cleanly indicates if the ball is unrecorded (when the ball state is dead) by setting the z-coordinate to -10. As a result, we can partially filter dead ball frames, but keep relevant dead ball frames around corners, throw-ins, prior to a free kick being taken etc. These frames can help with syncing and with analysis.

Now, I don't know if any other tracking data providers have something similar. If they do, please record them here, and share how they behave, then we can add this functionality to more providers.