posts: show length of videos and animations in thumbnails.

Show the length of videos and animated posts in the thumbnail. The
length is shown the top left corner in MM:SS format. This replaces the
play button icon.

Show a speaker icon instead of a music note icon for posts with sound.

Doing this requires doing `.includes(:media_asset)` in a bunch of
places to avoid N+1 queries when we access the post's duration.

app/logical/iqdb_client.rb

@@ -66,7 +66,7 @@ class IqdbClient
     def process_results(matches, low_similarity, high_similarity)
       matches = matches.select { |result| result["score"] >= low_similarity }
       post_ids = matches.map { |match| match["post_id"] }
-      posts = Post.where(id: post_ids).group_by(&:id).transform_values(&:first)
+      posts = Post.includes(:media_asset).where(id: post_ids).group_by(&:id).transform_values(&:first)
 
       matches = matches.map do |match|
         post = posts.fetch(match["post_id"], nil)

app/logical/post_query_builder.rb

@@ -489,10 +489,10 @@ class PostQueryBuilder
     relation
   end
 
-  def build
+  def build(includes: nil)
     validate!
 
-    relation = Post.all
+    relation = Post.includes(includes)
     relation = add_joins(relation)
     relation = metatags_match(metatags, relation)
     relation = tags_match(tags, relation)
@@ -514,8 +514,8 @@ class PostQueryBuilder
     relation
   end
 
-  def paginated_posts(page, small_search_threshold: Danbooru.config.small_search_threshold.to_i, **options)
-    posts = build.paginate(page, **options)
+  def paginated_posts(page, small_search_threshold: Danbooru.config.small_search_threshold.to_i, includes: nil, **options)
+    posts = build(includes: includes).paginate(page, **options)
     posts = optimize_search(posts, small_search_threshold)
     posts.load
   end

app/logical/post_sets/post.rb

@@ -107,7 +107,7 @@ module PostSets
         if is_random?
           get_random_posts.paginate(page, search_count: false, limit: per_page, max_limit: max_per_page).load
         else
-          normalized_query.paginated_posts(page, count: post_count, search_count: !post_count.nil?, limit: per_page, max_limit: max_per_page).load
+          normalized_query.paginated_posts(page, includes: :media_asset, count: post_count, search_count: !post_count.nil?, limit: per_page, max_limit: max_per_page).load
         end
       end
     end

app/logical/recommender_service.rb

@@ -59,7 +59,7 @@ module RecommenderService
   # Process a set of recommendations to filter out posts the user uploaded
   # themselves, or has already favorited, or that don't match a tag search.
   def process_recs(recs, post: nil, uploader: nil, favoriter: nil, tags: nil)
-    posts = Post.where(id: recs.map(&:first))
+    posts = Post.includes(:media_asset).where(id: recs.map(&:first))
     posts = posts.where.not(id: post.id) if post
     posts = posts.where.not(uploader_id: uploader.id) if uploader
     posts = posts.where.not(id: favoriter.favorites.select(:post_id)) if favoriter