Moodle 4.5 compatibility.

Author: lucaboesch

filter.php renamed to classes/text_filter.php

@@ -22,14 +22,16 @@
 use filter_embedquestion\token;
 use filter_embedquestion\utils;
 
+namespace filter_embedquestion;
+
 /**
  * A Moodle text filter to embed questions from the bank in content.
  *
  * @package   filter_embedquestion
  * @copyright 2018 The Open University
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class filter_embedquestion extends moodle_text_filter {
+class text_filter extends \core_filters\text_filter {
     /**
      * @var string Closing part of the embed token wrapper.
      */