BURs: don't update OP when approving BUR.

When approving or rejecting a BUR, don't edit the OP forum post to add
an EDIT: line stating the request has been approved. Instead just let
the embedded BUR state who it was approved by, and post a reply saying
that the request has been approved.

app/logical/d_text.rb

@@ -109,7 +109,7 @@ class DText
       end
 
       if obj.is_approved?
-        "The \"bulk update request ##{obj.id}\":/bulk_update_requests/#{obj.id} is active.\n\n#{embedded_script}"
+        "The \"bulk update request ##{obj.id}\":/bulk_update_requests/#{obj.id} has been approved by <@#{obj.approver.pretty_name}>.\n\n#{embedded_script}"
       elsif obj.is_pending?
         "The \"bulk update request ##{obj.id}\":/bulk_update_requests/#{obj.id} is pending approval.\n\n#{embedded_script}"
       elsif obj.is_rejected?

app/logical/forum_updater.rb

@@ -1,28 +1,13 @@
 class ForumUpdater
-  attr_reader :forum_topic, :forum_post
+  attr_reader :forum_topic
 
-  def initialize(forum_topic, options = {})
+  def initialize(forum_topic)
     @forum_topic = forum_topic
-    @forum_post = options[:forum_post]
   end
 
   def update(message)
-    return if forum_topic.nil?
-
     CurrentUser.scoped(User.system) do
-      create_response(message)
-
-      if forum_post
-        update_post(message)
-      end
+      forum_topic.forum_posts.create(body: message, skip_mention_notifications: true, creator: User.system)
     end
   end
-
-  def create_response(body)
-    forum_topic.forum_posts.create(body: body, skip_mention_notifications: true, creator: User.system)
-  end
-
-  def update_post(body)
-    forum_post.update(body: "#{forum_post.body}\n\nEDIT: #{body}", skip_mention_notifications: true)
-  end
 end

app/models/bulk_update_request.rb

@@ -60,14 +60,7 @@ class BulkUpdateRequest < ApplicationRecord
 
   module ApprovalMethods
     def forum_updater
-      @forum_updater ||= begin
-        post = if forum_topic
-          forum_post || forum_topic.forum_posts.first
-        else
-          nil
-        end
-        ForumUpdater.new(forum_topic, forum_post: post)
-      end
+      @forum_updater ||= ForumUpdater.new(forum_topic)
     end
 
     def approve!(approver)