[ticket/13654] Moving reporting into controller

Moving report.php's content into different services and controllers to
better comply with the MVC model.

Also implementing:
 * Replacement for reasons_display()
 * Adding assign_meta_refresh_var() to \controller\helper
 * Adding separate routes for easy configuration
 * Updating unit tests to expect to correct results
 * Add BC tests

PHPBB3-13654

phpBB/config/default/container/services.yml

@@ -13,6 +13,7 @@ imports:
     - { resource: services_notification.yml }
     - { resource: services_password.yml }
     - { resource: services_profilefield.yml }
+    - { resource: services_report.yml }
     - { resource: services_text_formatter.yml }
     - { resource: services_twig.yml }
     - { resource: services_user.yml }