MDL-75610 theme: Allow the activity title in Boost theme's secure layout

.upgradenotes/MDL-75610-2024111313224921.yml

@@ -0,0 +1,19 @@
+issueNumber: MDL-75610
+notes:
+  core:
+    - message: >
+        `\core\output\activity_header` now uses the `is_title_allowed()` method
+        when setting the title in the constructor.
+
+
+        This method has been improved to give priority to the 'notitle' option
+        in the theme config for the current page layout, over the top-level
+        option in the theme.
+
+
+        For example, the Boost theme sets
+        `$THEME->activityheaderconfig['notitle'] = true;` by default, but in its
+        `secure` pagelayout, it has `'notitle' = false`.
+
+        This prevents display of the title in all layouts except `secure`.
+      type: improved