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/artist.rb

@@ -426,7 +426,7 @@ class Artist < ApplicationRecord
     end
 
     def search(params)
-      q = where("true")
+      q = super
       params = {} if params.blank?
 
       case params[:name]
@@ -496,10 +496,6 @@ class Artist < ApplicationRecord
         q = q.unbanned
       end
 
-      if params[:id].present?
-        q = q.where("artists.id in (?)", params[:id].split(",").map(&:to_i))
-      end
-
       if params[:creator_name].present?
         q = q.where("artists.creator_id = (select _.id from users _ where lower(_.name) = ?)", params[:creator_name].tr(" ", "_").mb_chars.downcase)
       end