Add account migration UI (#11846)

Fix #10736

- Change data export to be available for non-functional accounts
- Change non-functional accounts to include redirecting accounts

app/controllers/concerns/export_controller_concern.rb

@@ -5,7 +5,10 @@ module ExportControllerConcern
 
   included do
     before_action :authenticate_user!
+    before_action :require_not_suspended!
     before_action :load_export
+
+    skip_before_action :require_functional!
   end
 
   private
@@ -27,4 +30,8 @@ module ExportControllerConcern
   def export_filename
     "#{controller_name}.csv"
   end
+
+  def require_not_suspended!
+    forbidden if current_account.suspended?
+  end
 end