burs/show: remove BUR update count estimate.

Remove the post update count estimate from BUR show pages. This was
complex, slow, and usually inaccurate since it assumed that requests in
a BUR had no overlap with each other, which usually wasn't the case.

app/jobs/tag_batch_change_job.rb

@@ -20,12 +20,6 @@ class TagBatchChangeJob < ApplicationJob
     end
   end
 
-  def self.estimate_update_count(antecedent, consequent)
-    CurrentUser.without_safe_mode do
-      Post.tag_match(antecedent).count
-    end
-  end
-
   def migrate_posts(normalized_antecedent, normalized_consequent)
     ::Post.tag_match(normalized_antecedent.join(" ")).find_each do |post|
       post.with_lock do

app/logical/alias_and_implication_importer.rb

@@ -78,24 +78,6 @@ class AliasAndImplicationImporter
     end
   end
 
-  def estimate_update_count
-    tokens = self.class.tokenize(text)
-    tokens.map do |token|
-      case token[0]
-      when :create_alias
-        TagAlias.new(antecedent_name: token[1], consequent_name: token[2]).estimate_update_count
-      when :create_implication
-        TagImplication.new(antecedent_name: token[1], consequent_name: token[2]).estimate_update_count
-      when :mass_update
-        TagBatchChangeJob.estimate_update_count(token[1], token[2])
-      when :change_category
-        Tag.find_by_name(token[1]).try(:post_count) || 0
-      else
-        0
-      end
-    end.sum
-  end
-
   def affected_tags
     tokens = self.class.tokenize(text)
     tokens.inject([]) do |all, token|

app/models/bulk_update_request.rb

@@ -206,10 +206,6 @@ class BulkUpdateRequest < ApplicationRecord
     status == "rejected"
   end
 
-  def estimate_update_count
-    AliasAndImplicationImporter.new(script, nil).estimate_update_count
-  end
-
   def update_notice
     TagChangeNoticeService.update_cache(
       AliasAndImplicationImporter.new(script, nil).affected_tags,

app/models/tag_relationship.rb

@@ -198,10 +198,6 @@ class TagRelationship < ApplicationRecord
     end
   end
 
-  def estimate_update_count
-    Post.fast_count(antecedent_name, skip_cache: true)
-  end
-
   def update_posts
     Post.without_timeout do
       Post.raw_tag_match(antecedent_name).find_each do |post|

app/views/bulk_update_requests/show.html.erb

@@ -9,7 +9,6 @@
       <li><strong>Creator</strong> <%= link_to_user @bulk_update_request.user %></li>
       <li><strong>Date</strong> <%= @bulk_update_request.created_at %></li>
       <li><strong>Status</strong>: <%= @bulk_update_request.status %></li>
-      <li><strong title="How many posts will be affected">Estimate</strong>: <%= @bulk_update_request.estimate_update_count %></li>
     </ul>
 
     <div style="margin: 1em 0;">