REFACTOR: Add full_url and display_name to User

Lets stop writing the same code over and over again.

app/models/topic_poster.rb

@@ -16,12 +16,6 @@ class TopicPoster < OpenStruct
   end
 
   def name_and_description
-    if SiteSetting.prioritize_username_in_ux? || user.name.blank?
-      name = user.username
-    else
-      name = user.name
-    end
-
-    I18n.t("js.user.avatar.name_and_description", name: name, description: description)
+    I18n.t("js.user.avatar.name_and_description", name: user.display_name, description: description)
   end
 end

app/models/user.rb

@@ -1461,6 +1461,18 @@ class User < ActiveRecord::Base
     username_lower == User.normalize_username(another_username)
   end
 
+  def full_url
+    "#{Discourse.base_url}/u/#{encoded_username}"
+  end
+
+  def display_name
+    if SiteSetting.prioritize_username_in_ux?
+      username
+    else
+      name.presence || username
+    end
+  end
+
   protected
 
   def badge_grant