Bugfix/4012 Correct closest page with template in rootline logic and refactor repository

[wazum]

What this PR does

This PR addresses issue #4012 by:

Correcting the logic for finding the closest page with an active system template within a given rootline.
* Ensured that the rootline data provided to the SystemTemplateRepository is interpreted correctly (root page first, current page last).
* Verified that the sorting logic correctly identifies the template on the current page or its nearest ancestor as the "closest".
* Updated unit tests to reflect the correct rootline structure and expected outcomes.

How to test

1. Verify that the integration tests in SystemTemplateRepositoryTest.php pass.
2. Manually test scenarios where a TYPO3 page tree has system templates on various levels of the rootline. Ensure that the system correctly identifies the template from the closest parent page in the rootline that has a template.
   • Example:
     • Root Page (no template)
       • Level 1 Page (no template)
         • Level 2 Page (has template A)
           • Current Page (has template B) -> Template B should be found.
     • Root Page (no template)
       • Level 1 Page (has template C)
         • Level 2 Page (no template)
           • Current Page (no template) -> Template C should be found.

Fixes: #4012

[dkd-kaehm]

The example in that pull-requiest is not the same as in issue, it is reversed(roots without templates in top and no-roots with templates on bottom).

To your issue, which should work currently without changes:
EXT:solr relies and uses the is_siteroot PIDs everywhere(beginning by tx_solr_indexqueue_item) and tries to initialize the TSFE to use the TypoScript, so the last chain link with TypoScript must always be the is_siteroot-Page with template.

EXT:solr requires a root page with template to work at all.
So you can assign a "empty or small" template to each of your micro-sites(whose root pages are marked as is_siteroot) and apply a whole TypoScript on some shared parent-page(try as non-root first, and if it works don't switch to is_siteroot because of #4353)

@wazum Please try the suggestion without your change and with.

[wazum]

Hm, that's exactly my problem as described in the issue:

I noticed the behaviour when I initialized the queue for a site that is inside another one (microsite). Also the outer site is inside a page that holds a sys_template record (not a site itself, just a page to hold TypoScript defaults for a number of sites).

• the container on top has a template (with general settings for all microsites/tenants) and no "Use as Root Page" set
• all microsites/tenants have a template and have "Use as Root Page" set (they are associated with a site/domain)

And this is solved with this pull request.
If you take a look at the original code, you see the problem instantly … it's just a query for all pages with a template and then returns any randomly (and not the one that is closest).
Please explain what is unclear or what you need to understand the issue.