[BUGFIX] Cast to string before trim (#1934)

Fixes PHP Runtime Deprecation Notice: trim(): Passing null to parameter #1 ($string) of type string is deprecated in Classes/ViewHelpers/Format/TrimViewHelper.php line 45

Author: chrisi51

Classes/ViewHelpers/Format/TrimViewHelper.php

@@ -40,9 +40,9 @@ public static function renderStatic(
         $characters = $arguments['characters'];
         $content = $renderChildrenClosure();
         if (!empty($characters)) {
-            $content = trim($content, $characters);
+            $content = trim((string) $content, $characters);
         } else {
-            $content = trim($content);
+            $content = trim((string) $content);
         }
         return $content;
     }