feat: wire loading state into video source loading

static/player/video.ts

@@ -1,6 +1,7 @@
 import Hls from "hls.js";
 
 import { attachHLSProfile } from "./hls_profile";
+import { setPlayerLoadState } from "./loading";
 import { state } from "./state";
 import { absoluteTimeFromDisplay, displayTimeFromAbsolute, invalidateBounds } from "./timeline";
 
@@ -53,6 +54,8 @@ export const loadVideoSource = (
     return;
   }
 
+  setPlayerLoadState("loading_media");
+
   const wasPlaying = !state.elements.video.paused;
   const prevDisplayTime = displayTimeFromAbsolute(state.elements.video.currentTime);
   const shouldPreservePosition = preservePosition && prevDisplayTime > 0;