Move AutoComplete::filterResults to new event dispatcher and GenericEvent

Signed-off-by: Joas Schilling <coding@schilljs.com>

core/Controller/AutoCompleteController.php

 use OCP\Collaboration\AutoComplete\AutoCompleteEvent;
 use OCP\Collaboration\AutoComplete\IManager;
 use OCP\Collaboration\Collaborators\ISearch;
+use OCP\EventDispatcher\IEventDispatcher;
 use OCP\IRequest;
-use OCP\Share;
 use OCP\Share\IShare;
-use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
 class AutoCompleteController extends Controller {
 	/** @var ISearch */
 	private $collaboratorSearch;
 	/** @var IManager */
 	private $autoCompleteManager;
-	/** @var EventDispatcherInterface */
+	/** @var IEventDispatcher */
 	private $dispatcher;
 
 	public function __construct(
 		IRequest $request,
 		ISearch $collaboratorSearch,
 		IManager $autoCompleteManager,
-		EventDispatcherInterface $dispatcher
+		IEventDispatcher $dispatcher
 	) {
 		parent::__construct($appName, $request);
 

lib/public/Collaboration/AutoComplete/AutoCompleteEvent.php

 
 namespace OCP\Collaboration\AutoComplete;
 
-use Symfony\Component\EventDispatcher\GenericEvent;
+use OCP\EventDispatcher\GenericEvent;
 
 /**
  * @since 16.0.0

tests/Core/Controller/AutoCompleteControllerTest.php

 use OC\Core\Controller\AutoCompleteController;
 use OCP\Collaboration\AutoComplete\IManager;
 use OCP\Collaboration\Collaborators\ISearch;
+use OCP\EventDispatcher\IEventDispatcher;
 use OCP\IRequest;
 use PHPUnit\Framework\MockObject\MockObject;
-use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Test\TestCase;
 
 class AutoCompleteControllerTest extends TestCase {
 	protected $collaboratorSearch;
 	/** @var  IManager|MockObject */
 	protected $autoCompleteManager;
-	/** @var  EventDispatcherInterface|MockObject */
+	/** @var  IEventDispatcher|MockObject */
 	protected $dispatcher;
 	/** @var  AutoCompleteController */
 	protected $controller;
 		$request = $this->createMock(IRequest::class);
 		$this->collaboratorSearch = $this->createMock(ISearch::class);
 		$this->autoCompleteManager = $this->createMock(IManager::class);
-		$this->dispatcher = $this->createMock(EventDispatcherInterface::class);
+		$this->dispatcher = $this->createMock(IEventDispatcher::class);
 
 		$this->controller = new AutoCompleteController(
 			'core',