Merge branch 'fivehundred_on_ui_help' into 'master'

Make a user available for the user variable

Fixes: #15289 

`current_user` is not available if one is signed out. 

Look for @dzaporozhets's user if available or just user with id `1`. Dz will work on GitLab.com and user with id 1 will work on dev. 

See merge request !3766

app/controllers/help_controller.rb

@@ -51,6 +51,7 @@ class HelpController < ApplicationController
   end
 
   def ui
+    @user = User.new(id: 0, name: 'John Doe', username: '@johndoe')
   end
 
   private

app/views/help/ui.html.haml

@@ -345,11 +345,11 @@
             %ul
               %li
                 %a.dropdown-menu-user-link.is-active{href: "#"}
-                  = link_to_member_avatar(current_user, size: 30)
+                  = link_to_member_avatar(@user, size: 30)
                   %strong.dropdown-menu-user-full-name
-                    = current_user.name
+                    = @user.name
                   .dropdown-menu-user-username
-                    = current_user.to_reference
+                    = @user.to_reference
 
   .example
     %div
@@ -372,11 +372,11 @@
               %ul
                 %li
                   %a.dropdown-menu-user-link.is-active{href: "#"}
-                    = link_to_member_avatar(current_user, size: 30)
+                    = link_to_member_avatar(@user, size: 30)
                     %strong.dropdown-menu-user-full-name
-                      = current_user.name
+                      = @user.name
                     .dropdown-menu-user-username
-                      = current_user.to_reference
+                      = @user.to_reference
           .dropdown-page-two
             .dropdown-title
               %button.dropdown-title-button.dropdown-menu-back{aria: {label: "Go back"}}