Fix problems with displayed encoded entities in javascript translatio…

…ns (#21322)

* Try to avoid displaying encoded entities in javascript translations

* updates expected UI test files

core/Translation/Translator.php

@@ -199,7 +199,7 @@ public function getJavascriptTranslations()
         $clientSideTranslations = array();
         foreach ($this->getClientSideTranslationKeys() as $id) {
             [$plugin, $key] = explode('_', $id, 2);
-            $clientSideTranslations[$id] = $this->getTranslation($id, $this->currentLanguage, $plugin, $key);
+            $clientSideTranslations[$id] = $this->decodeEntitiesSafeForHTML($this->getTranslation($id, $this->currentLanguage, $plugin, $key));
         }
 
         $js = 'var translations = ' . json_encode($clientSideTranslations) . ';';
@@ -208,6 +208,32 @@ public function getJavascriptTranslations()
         return $js;
     }
 
+    /**
+     * Decodes all entities in the given string except of > and <
+     *
+     * @param string $text
+     * @return string
+     */
+    private function decodeEntitiesSafeForHTML(string $text): string
+    {
+        // replace encoded html tag entities, as they need to remain encoded
+        $text = str_replace(
+            ['>', '<'],
+            ['###gt###', '###lt###'],
+            $text
+        );
+
+        // decode all remaining entities
+        $text = html_entity_decode($text);
+
+        // recover encoded html tag entities
+        return str_replace(
+            ['###gt###', '###lt###'],
+            ['>', '<'],
+            $text
+        );
+    }
+
     /**
      * Returns the list of client side translations by key. These translations will be outputted
      * to the translation JavaScript.