First pass at the new video tile designs

Here, I've begun updating the styles of video tiles to match the new designs. Not yet updated: the local volume option is supposed to go inside an overflow menu now, but I haven't gotten to that yet.

To make the outlines on hovered / speaking tiles show up properly, I have to remove the usePageFocusStyle hack, which was preventing CSS outlines from being used for anything other than focus rings. I honestly can't tell what problem it was solving in the first place: focus rings still appear to behave as expected throughout the application.

src/video-grid/VideoGrid.tsx

@@ -1082,7 +1082,7 @@ export function VideoGrid<T>({
             y?: number;
             width?: number;
             height?: number;
-          } = { shadow: 1, scale: 0, opacity: 0 };
+          } = { shadow: 0, scale: 0, opacity: 0 };
           let reset = false;
 
           if (!tilePositionsWereValid) {
@@ -1105,7 +1105,7 @@ export function VideoGrid<T>({
             scale: remove ? 0 : 1,
             opacity: remove ? 0 : 1,
             zIndex: tilePosition.zIndex,
-            shadow: 1,
+            shadow: oneOnOneLayout && tile.item.local ? 1 : 0,
             shadowSpread: oneOnOneLayout && tile.item.local ? 1 : 0,
             from,
             reset,