fix(symfony): allow to merge array with string in global defaults (api-platform#7037)

* fix: merge an array and not a string

* fix: merge an array only if upperkey is 'Formats'

* fix: cs

* fix: transform string to array globally

Co-authored-by: Antoine Bluchet <[email protected]>

---------

Co-authored-by: Antoine Bluchet <[email protected]>

Author: Crovitche-1623

src/Metadata/Resource/Factory/OperationDefaultsTrait.php

@@ -63,6 +63,10 @@ private function addGlobalDefaults(ApiResource|Operation $operation): ApiResourc
             $currentValue = $operation->{$getter}();
 
             if (\is_array($currentValue) && $currentValue) {
+                if (\is_string($value)) {
+                    $value = [$value];
+                }
+
                 $operation = $operation->{'with'.$upperKey}(array_merge($value, $currentValue));
             }