Feature: #90994 - Mark current page in fluid_styled_content menu content elements

See Issue #90994

Description

All menu content elements related to page navigation reflect the “current” state of a page now.

The resulting HTML of these page link lists is then:

<li>
    <a aria-current="page" > ...
</li>

Impact

The aria attribute aria-current=”page” is added to a-tag of a menu-item.

For styling with CSS the attribute of the link can be used:

[aria-current="page"] {
    /* Special style for the current page link */
}
[aria-current="page"]:hover {
    /* Special style for the current page link when hovered */
}
[aria-current="page"]::before {
    /* Special virtual element for additions like chevrons, etc. */
}