Rename DataTransformerFilterInterface to DataTransformerInterface

The DataTransformerFilterInterface has been renamed to DataTransformerInterface to reflect expanded functionality. Now, this interface can be implemented not only by @see{FilterInterface}, but also by @see{AggregatorInterface}. This change allows transforming existing data in saved exports and replacing it with some default values, or new default values.

src/Bundle/ChillMainBundle/Export/DataTransformerInterface.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\MainBundle\Export;
+
+/**
+ * Transform data from filter.
+ *
+ * This interface defines a method for transforming filter's form data before it is processed.
+ *
+ * You can implement this interface on @see{FilterInterface} or @see{AggregatorInterface}, to allow to transform existing data in saved exports
+ * and replace it with some default values, or new default values.
+ */
+interface DataTransformerInterface
+{
+    public function transformData(?array $before): array;
+}