FEATURE: Site settings defaults per locale

This change-set allows setting different defaults for different locales. 

It also:

- Adds extensive testing around site setting validation

- raises deprecation error if site setting has the default property based on env

- relocated site settings for dev and tests in the initializer

- deprecated client_setting in the site setting's loading process

- ensure it raises when a enum site setting being set

- default_locale is promoted to `required` category.

- fixes incorrect default setting and validation

- fixes ensure type check for site settings

- creates a benchmark for site setting

- sets reasonable defaults for Chinese

config/environments/development.rb

@@ -59,6 +59,9 @@ Discourse::Application.configure do
   end
 
   config.after_initialize do
+    SiteSetting.defaults.set_regardless_of_locale(:port, 3000)
+    SiteSetting.refresh!
+
     if ENV['BULLET']
       Bullet.enable = true
       Bullet.rails_logger = true

config/environments/test.rb

@@ -46,4 +46,22 @@ Discourse::Application.configure do
     config.logger = Logger.new(nil)
     config.log_level = :fatal
   end
+
+  config.after_initialize do
+    SiteSetting.defaults.tap do |s|
+      s.set_regardless_of_locale(:s3_upload_bucket, 'bucket')
+      s.set_regardless_of_locale(:min_post_length, 5)
+      s.set_regardless_of_locale(:min_first_post_length, 5)
+      s.set_regardless_of_locale(:min_private_message_post_length, 10)
+      s.set_regardless_of_locale(:crawl_images, false)
+      s.set_regardless_of_locale(:download_remote_images_to_local, false)
+      s.set_regardless_of_locale(:unique_posts_mins, 0)
+      s.set_regardless_of_locale(:queue_jobs, false)
+      # disable plugins
+      if ENV['LOAD_PLUGINS'] == '1'
+        s.set_regardless_of_locale(:discourse_narrative_bot_enabled, false)
+      end
+    end
+    SiteSetting.refresh!
+  end
 end