Revert "REVERT: message bus changes"

This reverts commit 4820d5c7b0.

config/initializers/100-i18n.rb

@@ -0,0 +1,10 @@
+# order: after 02-freedom_patches.rb
+
+require 'i18n/backend/discourse_i18n'
+I18n.backend = I18n::Backend::DiscourseI18n.new
+I18n.config.missing_interpolation_argument_handler = proc { throw(:exception) }
+I18n.init_accelerator!
+
+unless Rails.env.test?
+  MessageBus.subscribe("/i18n-flush") { I18n.reload! }
+end