DEV: Adopt post list component and new posts route front-end (#30604)

Recently we introduced a new `PostList` component (d886c55f63). In this update, we make broader adoption of this component. In particular, these areas include using the new component in the user activity stream pages, user's deleted posts, and pending posts page. This update also takes the existing `posts` route and adds a barebones front-end for it to view posts all in one page.

---------

Co-authored-by: David Taylor <david@taylorhq.com>

app/serializers/group_post_serializer.rb

@@ -5,15 +5,43 @@ require_relative "post_item_excerpt"
 class GroupPostSerializer < ApplicationSerializer
   include PostItemExcerpt
 
-  attributes :id, :created_at, :title, :url, :category_id, :post_number, :topic_id, :post_type
+  attributes :id,
+             :created_at,
+             :topic_id,
+             :topic_title,
+             :topic_slug,
+             :topic_html_title,
+             :url,
+             :category_id,
+             :post_number,
+             :posts_count,
+             :post_type,
+             :username,
+             :name,
+             :avatar_template,
+             :user_title,
+             :primary_group_name
 
+  # TODO(keegan): Remove `embed: :object` after updating references in discourse-reactions
   has_one :user, serializer: GroupPostUserSerializer, embed: :object
   has_one :topic, serializer: BasicTopicSerializer, embed: :object
 
-  def title
+  def topic_title
     object.topic.title
   end
 
+  def topic_html_title
+    object.topic.fancy_title
+  end
+
+  def topic_slug
+    object.topic.slug
+  end
+
+  def posts_count
+    object.topic.posts_count
+  end
+
   def include_user_long_name?
     SiteSetting.enable_names?
   end
@@ -21,4 +49,24 @@ class GroupPostSerializer < ApplicationSerializer
   def category_id
     object.topic.category_id
   end
+
+  def username
+    object&.user&.username
+  end
+
+  def name
+    object&.user&.name
+  end
+
+  def avatar_template
+    object&.user&.avatar_template
+  end
+
+  def user_title
+    object&.user&.title
+  end
+
+  def primary_group_name
+    object&.user&.primary_group&.name
+  end
 end

app/serializers/post_serializer.rb

@@ -17,6 +17,7 @@ class PostSerializer < BasicPostSerializer
 
   attributes :post_number,
              :post_type,
+             :posts_count,
              :updated_at,
              :reply_count,
              :reply_to_post_number,
@@ -84,12 +85,14 @@ class PostSerializer < BasicPostSerializer
              :last_wiki_edit,
              :locked,
              :excerpt,
+             :truncated,
              :reviewable_id,
              :reviewable_score_count,
              :reviewable_score_pending_count,
              :user_suspended,
              :user_status,
-             :mentioned_users
+             :mentioned_users,
+             :post_url
 
   def initialize(object, opts)
     super(object, opts)
@@ -99,6 +102,10 @@ class PostSerializer < BasicPostSerializer
     end
   end
 
+  def post_url
+    object&.url
+  end
+
   def topic_slug
     topic&.slug
   end
@@ -119,6 +126,14 @@ class PostSerializer < BasicPostSerializer
     @add_excerpt
   end
 
+  def include_truncated?
+    @add_excerpt
+  end
+
+  def truncated
+    true
+  end
+
   def topic_title
     topic&.title
   end
@@ -127,6 +142,10 @@ class PostSerializer < BasicPostSerializer
     topic&.fancy_title
   end
 
+  def posts_count
+    topic&.posts_count
+  end
+
   def category_id
     topic&.category_id
   end