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/ValueObject/FormattedNotification.php

@@ -0,0 +1,65 @@
+<?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\ValueObject;
+
+use Friendica\BaseDataTransferObject;
+
+/**
+ * A view-only object for printing item notifications to the frontend
+ */
+class FormattedNotification extends BaseDataTransferObject
+{
+	const SYSTEM   = 'system';
+	const PERSONAL = 'personal';
+	const NETWORK  = 'network';
+	const INTRO    = 'intro';
+	const HOME     = 'home';
+
+	/** @var string */
+	protected $label = '';
+	/** @var string */
+	protected $link = '';
+	/** @var string */
+	protected $image = '';
+	/** @var string */
+	protected $url = '';
+	/** @var string */
+	protected $text = '';
+	/** @var string */
+	protected $when = '';
+	/** @var string */
+	protected $ago = '';
+	/** @var boolean */
+	protected $seen = false;
+
+	public function __construct(string $label, string $link, string $image, string $url, string $text, string $when, string $ago, bool $seen)
+	{
+		$this->label = $label ?? '';
+		$this->link  = $link  ?? '';
+		$this->image = $image ?? '';
+		$this->url   = $url   ?? '';
+		$this->text  = $text  ?? '';
+		$this->when  = $when  ?? '';
+		$this->ago   = $ago   ?? '';
+		$this->seen  = $seen  ?? false;
+	}
+}