Part-10 dashboard navigation change

Add this link to the existing Student Dashboard sidebar/menu, without changing
Teacher/Admin authentication or existing Student authentication:

<a href="<?=studentDashEscape(BASE_URL)?>student/exams/index.php">
    <i class="fa-solid fa-file-pen me-2"></i>My Exams
</a>

The supplied Part-10 package does not overwrite the existing dashboard.php.
This is intentional: the current Part-9 dashboard is already working and
should remain untouched until the My Exams module is verified.