Fix PostgreSQL load when linking in announcements (#13250)

* Fix PostgreSQL load when linking in announcements

Fixes #13245 by caching status lookups

Since statuses are supposed to be known already and we only
need their URLs and a few other things, caching them should
be fine.

Since it's only used by announcements so far, there won't
be much statuses to cache.

* Perform status lookup when saving announcements, not when rendering them

* Change EntityCache#status to fetch URLs instead of looking into the database

* Move announcement link lookup to publishing worker

* Address issues pointed out during review

app/workers/publish_scheduled_announcement_worker.rb

@@ -5,15 +5,24 @@ class PublishScheduledAnnouncementWorker
   include Redisable
 
   def perform(announcement_id)
-    announcement = Announcement.find(announcement_id)
+    @announcement = Announcement.find(announcement_id)
 
-    announcement.publish! unless announcement.published?
+    refresh_status_ids!
 
-    payload = InlineRenderer.render(announcement, nil, :announcement)
+    @announcement.publish! unless @announcement.published?
+
+    payload = InlineRenderer.render(@announcement, nil, :announcement)
     payload = Oj.dump(event: :announcement, payload: payload)
 
     FeedManager.instance.with_active_accounts do |account|
       redis.publish("timeline:#{account.id}", payload) if redis.exists("subscribed:timeline:#{account.id}")
     end
   end
+
+  private
+
+  def refresh_status_ids!
+    @announcement.status_ids = Status.from_text(@announcement.text).map(&:id)
+    @announcement.save
+  end
 end