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/Actions/ActivityService.php

@@ -1,6 +1,7 @@
 <?php namespace BookStack\Actions;
 
 use BookStack\Auth\Permissions\PermissionService;
+use BookStack\Entities\Book;
 use BookStack\Entities\Entity;
 
 class ActivityService
@@ -68,7 +69,7 @@ class ActivityService
      * Removes the entity attachment from each of its activities
      * and instead uses the 'extra' field with the entities name.
      * Used when an entity is deleted.
-     * @param Entity $entity
+     * @param \BookStack\Entities\Entity $entity
      * @return mixed
      */
     public function removeEntity(Entity $entity)
@@ -106,7 +107,7 @@ class ActivityService
     /**
      * Gets the latest activity for an entity, Filtering out similar
      * items to prevent a message activity list.
-     * @param Entity $entity
+     * @param \BookStack\Entities\Entity $entity
      * @param int $count
      * @param int $page
      * @return array