[Video] Visibility detection view (#4741)

Co-authored-by: Samuel Newman <10959775+mozzius@users.noreply.github.com>

src/view/com/util/post-embeds/VideoEmbedInner/VideoWebControls.tsx

@@ -0,0 +1,16 @@
+import React from 'react'
+import type Hls from 'hls.js'
+
+export function Controls({}: {
+  videoRef: React.RefObject<HTMLVideoElement>
+  hlsRef: React.RefObject<Hls | undefined>
+  active: boolean
+  setActive: () => void
+  focused: boolean
+  setFocused: (focused: boolean) => void
+  onScreen: boolean
+  fullscreenRef: React.RefObject<HTMLDivElement>
+  hasSubtitleTrack: boolean
+}): React.ReactElement {
+  throw new Error('Web-only component')
+}