Add feature option to enable CC by default

Have an option to enable Closed Captions to enable by default when viewing a video. Sometimes it's practical to have a different audio track to what is actually displayed as text in the callouts. enabling CC as active by default allows the audio track display while the user is watching the video when their device may be set to silent. It's also very useful for sharing on social media where the video may auto play even before they select it. There is a very high percentage of viewers on social media that watch videos in silent mode. Especially on LinkedIn (our primary channel). The CC toggle button is also very small and I suspect many users don't notice the option.