[BUGFIX] Add additional GetVars to workspace preview url

Resolves: #87147
Releases: master, 9.5
Change-Id: Ia909104bc663d4191f21cb1bf0e25c0212388e2f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/59133


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>

typo3/sysext/workspaces/Classes/Hook/BackendUtilityHook.php

@@ -45,6 +45,7 @@ class BackendUtilityHook
     {
         if ($GLOBALS['BE_USER']->workspace !== 0) {
             $viewScript = GeneralUtility::makeInstance(PreviewUriBuilder::class)->buildUriForWorkspaceSplitPreview((int)$pageUid, false);
+            $viewScript .= $additionalGetVars ?: '';
         }
     }