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/Exception/NotificationCreationInterceptedException.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Friendica\Navigation\Notifications\Exception;
+
+class NotificationCreationInterceptedException extends \Exception
+{
+}