[BUGFIX] Add sys_language_uid for PageSlugCandidateProvider

When using routing and custom enhancers to find out
what page translation was exactly used to build
special logic for Page resolving, the two
language-related properties "sys_language_uid"
and "l18n_cfg" are now loaded (and thus, added to the
"_page" property of a Route) as well.

This is useful as l10n_parent is already loaded anyways.

Resolves: #98042
Releases: main, 11.5, 10.4
Change-Id: I23f964d5d22f27a9affebfeae87906d9549efda0
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75229
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>

typo3/sysext/core/Classes/Routing/PageSlugCandidateProvider.php

@@ -203,7 +203,7 @@ protected function getPagesFromDatabaseForCandidates(array $slugCandidates, int
             ->add(GeneralUtility::makeInstance(WorkspaceRestriction::class, $workspaceId));
 
         $statement = $queryBuilder
-            ->select('uid', 'l10n_parent', 'pid', 'slug', 'mount_pid', 'mount_pid_ol', 't3ver_state', 'doktype', 't3ver_wsid', 't3ver_oid')
+            ->select('uid', 'sys_language_uid', 'l10n_parent', 'l18n_cfg', 'pid', 'slug', 'mount_pid', 'mount_pid_ol', 't3ver_state', 'doktype', 't3ver_wsid', 't3ver_oid')
             ->from('pages')
             ->where(
                 $queryBuilder->expr()->eq(