Add content to the Remote Census Configuration tab

- Render remote census configuration content on settings index.
 - Update type method from Setting
   On Admin::SettingsController#index we are using 'all_settings' to
   group all settings by 'type' method.
   'type' method return the first part of key when split by '.'
   To allow use by example: all_settings["remote_census.general"]
   and recover only settings related with this key we have added new
   'elsif' on 'type' method.

app/models/setting.rb

@@ -10,6 +10,8 @@ class Setting < ApplicationRecord
   def type
     if %w[feature process proposals map html homepage uploads].include? prefix
       prefix
+    elsif %w[remote_census].include? prefix
+      key.rpartition(".").first
     else
       "configuration"
     end