Introduce new DI container

- Adding Friendica\DI class for getting dynamic classes
- Replacing BaseObject::getApp() with this class

src/Module/PublicRSAKey.php

@@ -4,6 +4,7 @@ namespace Friendica\Module;
 
 use ASN_BASE;
 use Friendica\BaseModule;
+use Friendica\DI;
 use Friendica\Model\User;
 use Friendica\Network\HTTPException\BadRequestException;
 
@@ -14,7 +15,7 @@ class PublicRSAKey extends BaseModule
 {
 	public static function rawContent(array $parameters = [])
 	{
-		$app = self::getApp();
+		$app = DI::app();
 
 		// @TODO: Replace with parameter from router
 		if ($app->argc !== 2) {