Allow LoadControl.shouldContinueLoading accept playWhenReady as a parameter

[colinkho]

Motivation: Load Control requires different min and max buffer values depending if the player is playing or paused.

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[colinkho]

Amended commit and force pushed to correct username to allow detection of CLA

[tonihei]

Thanks, I'll continue the merge process internally and will probably force-push too with additional formatting updates etc.

[tonihei]

This is merged now. You may have seen it already, but we updated the pull request to move the parameters class inside LoadControl itself and also used it for shouldStartPlayback.