Feature: #19856 - Set special ATagParams for links to access restricted pages

See forge#19856

Description

A new TypoScript option is introduced which allows additional tag attributes to be set to links of pages which are access restricted by frontend user group restriction. Usually these links will not be generated, but it is possible to link them to another page, for example, a special login page:

config.typolinkLinkAccessRestrictedPages = 13
config.typolinkLinkAccessRestrictedPages_addParams = &originalPage=###PAGE_ID###

The resulting link to a access-restricted page (e.g. 22) looks like this: <a href="/login?originalPage=22">My page</a>

The newly introduced option config.typolinkLinkAccessRestrictedPages.ATagParams allows custom attributes to be added to the current anchor tag.

config.typolinkLinkAccessRestrictedPages.ATagParams = class="restricted"

This will result in <a href="/login?originalPage=22" class="restricted">My page</a>.

When generating menus via HMENU, the new ATagParams option is also available for custom settings:

page.10 = HMENU
page.10.showAccessRestrictedPages = 13
page.10.showAccessRestrictedPages.ATagParams = class="access-restricted"

Impact

Allowing integrators to set custom ATagParams such as class attributes or arbitrary data attributes to use client-side styling via CSS or JavaScript event listeners to handle such links differently.