FEATURE: Decorate topic-level bookmark button with reminder time (#9426)

* Show the correct bookmark with clock icon when topic-level bookmark reminder time is set and show the time of the reminder in the title on hover.
* Add a new bookmark lib and reminder time formatting function to show time with today/tomorrow shorthand for readability. E.g. tomorrow at 8:00am instead of Apr 16 2020 at 8:00am. This only applies to today + tomorrow, future dates are still treated the same.

app/serializers/topic_view_serializer.rb

@@ -61,6 +61,7 @@ class TopicViewSerializer < ApplicationSerializer
     :is_warning,
     :chunk_size,
     :bookmarked,
+    :bookmark_reminder_at,
     :message_archived,
     :topic_timer,
     :private_topic_timer,
@@ -192,6 +193,14 @@ class TopicViewSerializer < ApplicationSerializer
     end
   end
 
+  def include_bookmark_reminder_at?
+    SiteSetting.enable_bookmarks_with_reminders? && bookmarked
+  end
+
+  def bookmark_reminder_at
+    object.first_post_bookmark_reminder_at
+  end
+
   def topic_timer
     TopicTimerSerializer.new(object.topic.public_topic_timer, root: false)
   end