MDL-78477 qbank_history: Fix and improve UI for edit menu delete option

Changes done to fix the warnings thrown in the history view when the
last version of a question is deleted and improved UI to display the
message and a Continue button, to navigate back to the Question bank.

question/bank/history/classes/question_history_view.php

@@ -175,7 +175,7 @@ protected function build_query(): void {
      * Display the header for the question bank in the history page to include question name and type.
      */
     public function display_question_bank_header(): void {
-        global $PAGE, $DB;
+        global $PAGE, $DB, $OUTPUT;
         $sql = 'SELECT q.*
                  FROM {question} q
                  JOIN {question_versions} qv ON qv.questionid = q.id
@@ -187,13 +187,19 @@ public function display_question_bank_header(): void {
                                       WHERE be.id = qbe.id)
                   AND qbe.id = ?';
         $latestquestiondata = $DB->get_record_sql($sql, [$this->entryid]);
-        $historydata = [
-            'questionname' => $latestquestiondata->name,
-            'returnurl' => $this->basereturnurl,
-            'questionicon' => print_question_icon($latestquestiondata)
-        ];
-        // Header for the page before the actual form from the api.
-        echo $PAGE->get_renderer('qbank_history')->render_history_header($historydata);
+        if ($latestquestiondata) {
+            $historydata = [
+                'questionname' => $latestquestiondata->name,
+                'returnurl' => $this->basereturnurl,
+                'questionicon' => print_question_icon($latestquestiondata)
+            ];
+            // Header for the page before the actual form from the api.
+            echo $PAGE->get_renderer('qbank_history')->render_history_header($historydata);
+        } else {
+            // Continue when all the question versions are deleted.
+            echo $OUTPUT->notification(get_string('allquestionversionsdeleted', 'qbank_history'), 'notifysuccess');
+            echo $OUTPUT->continue_button($this->basereturnurl);
+        }
     }
 
     public function is_listing_specific_versions(): bool {

question/bank/history/lang/en/qbank_history.php

@@ -23,6 +23,7 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+$string['allquestionversionsdeleted'] = 'All versions of this question have been deleted.';
 $string['close_history'] = 'Close';
 $string['history_action'] = 'History';
 $string['history_header'] = 'Question history';

question/bank/history/tests/behat/question_history_action.feature

@@ -43,3 +43,15 @@ Feature: Use the qbank plugin manager page for question history
     And the "History" action should not exist for the "First question" question in the question bank
     And I click on "#qbank-history-close" "css_element"
     And the "History" action should exist for the "First question" question in the question bank
+
+  @javascript
+  Scenario: Delete question from the history using Edit question menu
+    Given I am on the "Test quiz" "mod_quiz > question bank" page logged in as "admin"
+    And I choose "History" action for "First question" in the question bank
+    When I choose "Delete" action for "First question" in the question bank
+    And I press "Delete"
+    And I should not see "First question"
+    Then I should see "All versions of this question have been deleted."
+    And I click on "Continue" "button"
+    And I should see "Question bank"
+    And I should not see "First question"