Improve the editing experience for live videos

Apparently we weren't using VideoJS's new live UI (I thought we were), which caused issues like "the progress bar is not present on the video."

thrimbletrimmer/scripts/common.js

@@ -49,7 +49,7 @@ async function loadVideoPlayer(playlistURL) {
 
 	let defaultOptions = {
 		sources: [{ src: rangedPlaylistURL }],
-		liveui: false,
+		liveui: true,
 		controls: true,
 		autoplay: false,
 		playbackRates: PLAYBACK_RATES,