Entity Repo & Controller Refactor (#1690)

* Started mass-refactoring of the current entity repos

* Rewrote book tree logic

- Now does two simple queries instead of one really complex one.
- Extracted logic into its own class.
- Remove model-level akward union field listing.
- Logic now more readable than being large separate query and
compilation functions.

* Extracted and split book sort logic

* Finished up Book controller/repo organisation

* Refactored bookshelves controllers and repo parts

* Fixed issues found via phpunit

* Refactored Chapter controller

* Updated Chapter export controller

* Started Page controller/repo refactor

* Refactored another chunk of PageController

* Completed initial pagecontroller refactor pass

* Fixed tests and continued reduction of old repos

* Removed old page remove and further reduced entity repo

* Removed old entity repo, split out page controller

* Ran phpcbf and split out some page content methods

* Tidied up some EntityProvider elements

* Fixed issued caused by viewservice change

app/Auth/User.php

@@ -53,13 +53,24 @@ class User extends Model implements AuthenticatableContract, CanResetPasswordCon
      */
     protected $permissions;
 
+    /**
+     * This holds the default user when loaded.
+     * @var null|User
+     */
+    protected static $defaultUser = null;
+
     /**
      * Returns the default public user.
      * @return User
      */
     public static function getDefault()
     {
-        return static::where('system_name', '=', 'public')->first();
+        if (!is_null(static::$defaultUser)) {
+            return static::$defaultUser;
+        }
+        
+        static::$defaultUser = static::where('system_name', '=', 'public')->first();
+        return static::$defaultUser;
     }
 
     /**