properly display alt text for videos (#8802)

The alt text is already properly federated and given by the API,
it is just not displayed properly by the client.

packages/client/src/components/media-video.vue

@@ -8,7 +8,8 @@
 <div v-else class="kkjnbbplepmiyuadieoenjgutgcmtsvu">
 	<video
 		:poster="video.thumbnailUrl"
-		:title="video.name"
+		:title="video.comment"
+		:alt="video.comment"
 		preload="none"
 		controls
 		@contextmenu.stop