MDL-77328 qtype_truefalse: Refactor for PHP 8.2 compatibility

This commit addresses the following issues and improvements in the
qtype_truefalse class:

- Added missing class properties:
 - public $truefeedbackformat
 - public $falsefeedbackformat
 - public $showstandardinstruction
- Updated qtype_truefalse_question to include type hinting for better
  IDE support.

question/type/truefalse/question.php

@@ -41,6 +41,15 @@ class qtype_truefalse_question extends question_graded_automatically {
     public $trueanswerid;
     public $falseanswerid;
 
+    /** @var int the format of the true feedback. */
+    public $truefeedbackformat;
+
+    /** @var int the format of the false feedback. */
+    public $falsefeedbackformat;
+
+    /** @var bool true to show the standard instruction, otherwise hide it. */
+    public $showstandardinstruction;
+
     public function get_expected_data() {
         return array('answer' => PARAM_INT);
     }

question/type/truefalse/questiontype.php

@@ -142,11 +142,9 @@ class qtype_truefalse extends question_type {
     protected function initialise_question_instance(question_definition $question, $questiondata) {
         parent::initialise_question_instance($question, $questiondata);
         $answers = $questiondata->options->answers;
-        if ($answers[$questiondata->options->trueanswer]->fraction > 0.99) {
-            $question->rightanswer = true;
-        } else {
-            $question->rightanswer = false;
-        }
+
+        /** @var qtype_truefalse_question $question */
+        $question->rightanswer = $answers[$questiondata->options->trueanswer]->fraction > 0.99;
         $question->truefeedback =  $answers[$questiondata->options->trueanswer]->feedback;
         $question->falsefeedback = $answers[$questiondata->options->falseanswer]->feedback;
         $question->truefeedbackformat =

question/type/truefalse/renderer.php

@@ -37,6 +37,7 @@ class qtype_truefalse_renderer extends qtype_renderer {
     public function formulation_and_controls(question_attempt $qa,
             question_display_options $options) {
 
+        /** @var qtype_truefalse_question $question */
         $question = $qa->get_question();
         $response = $qa->get_last_qt_var('answer', '');