FEATURE: filter personal messages by tags

app/controllers/list_controller.rb

@@ -134,6 +134,7 @@ class ListController < ApplicationController
   def self.generate_message_route(action)
     define_method("#{action}") do
       list_opts = build_topic_list_options
+      list_opts[:show_pm_tags] = true if guardian.can_tag_pms?
       target_user = fetch_user_from_params({ include_inactive: current_user.try(:staff?) }, [:user_stat, :user_option])
       guardian.ensure_can_see_private_messages!(target_user.id)
       list = generate_list_for(action.to_s, target_user, list_opts)