Add UIBlocks to twig (generic parser and node)

# Conflicts:
#	pages/run_query.php
#	test/VisualTest/Backoffice/RenderAllUiBlocks.php

sources/application/UI/Base/AbstractUIBlockFactory.php

@@ -0,0 +1,25 @@
+<?php
+/**
+ * @copyright   Copyright (C) 2010-2021 Combodo SARL
+ * @license     http://opensource.org/licenses/AGPL-3.0
+ */
+
+
+namespace Combodo\iTop\Application\UI\Base;
+
+
+abstract class AbstractUIBlockFactory implements iUIBlockFactory
+{
+	public const TWIG_TAG_NAME = 'UIBlock';
+	public const UI_BLOCK_CLASS_NAME = "Combodo\\iTop\\Application\\UI\\Base\\UIBlock";
+
+	public static function GetTwigTagName(): string
+	{
+		return static::TWIG_TAG_NAME;
+	}
+
+	public static function GetUIBlockClassName(): string
+	{
+		return static::UI_BLOCK_CLASS_NAME;
+	}
+}