Merge branch 'hotfix/fix_be_language_at_trans_models' into 'release/2.3.0'

Fix the change of language in BE navigation on activated trans. model

See merge request metamodels/core!376

Author: zonky2

src/Events/DatabaseBackedListener.php

@@ -268,6 +268,11 @@ public function createMetaModel(CreateMetaModelEvent $event)
 
         if (isset($this->instancesByTable[$metaModelName = $event->getMetaModelName()])) {
             $event->setMetaModel($this->instancesByTable[$metaModelName]);
+            $metaModel = $event->getMetaModel();
+            if ($metaModel instanceof ITranslatedMetaModel) {
+                // @deprecated usage of TL_LANGUAGE - remove for Contao 5.0.
+                $metaModel->selectLanguage(LocaleUtil::formatAsLocale($GLOBALS['TL_LANGUAGE'] ?? 'en'));
+            }
 
             return;
         }