Add new paradigm classes for notify

- Create BaseDepository class
- Create Entity, Collection, Factory and Depository classes
- Create FormattedNotification Entity, Collection and Factory to remove business logic from Notify repository
- Create new NotificationCreationIntercepted exception to allow addons to cancel notification creation
- Remove unused frio notifications/notify.tpl template

src/Navigation/Notifications/Collection/FormattedNotifications.php

@@ -0,0 +1,36 @@
+<?php
+/**
+ * @copyright Copyright (C) 2010-2021, the Friendica project
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Navigation\Notifications\Collection;
+
+use Friendica\BaseCollection;
+use Friendica\Navigation\Notifications\ValueObject;
+
+class FormattedNotifications extends BaseCollection
+{
+	/**
+	 * @return ValueObject\FormattedNotification
+	 */
+	public function current(): ValueObject\FormattedNotification
+	{
+		return parent::current();
+	}
+}