Fix #3430: Accept the search[id] param in all controllers.

* Allow every controller to take the `search[id]` param.

* Parse the `search[id]` param the same way that the `id:<N>` metatag is
  parsed. So `search[id]=1,2,3`, `search[id]=<42`, `search[id]=1..10`, for
  example, are all accepted.

app/models/forum_topic.rb

@@ -73,11 +73,8 @@ class ForumTopic < ApplicationRecord
     end
 
     def search(params)
-      q = permitted
-
-      if params[:id].present?
-        q = q.where(id: params[:id].split(",").map(&:to_i))
-      end
+      q = super
+      q = q.permitted
 
       if params[:mod_only].present?
         q = q.where("min_level >= ?", MIN_LEVELS[:Moderator])