models: set more creator names explicitly.

Set creators explicitly for bans, BURs, comment votes, and posts.

app/models/forum_post.rb

@@ -10,7 +10,6 @@ class ForumPost < ApplicationRecord
   has_one :tag_implication
   has_one :bulk_update_request
 
-  before_validation :initialize_is_deleted, :on => :create
   before_save :update_dtext_links, if: :dtext_links_changed?
   before_create :autoreport_spam
   after_create :update_topic_updated_at_on_create
@@ -183,10 +182,6 @@ class ForumPost < ApplicationRecord
     topic.response_count -= 1
   end
 
-  def initialize_is_deleted
-    self.is_deleted = false if is_deleted.nil?
-  end
-
   def quoted_response
     DText.quote(body, creator.name)
   end