Add guard to block signatures on related entities without objects

Implemented a guard to prevent signatures on related entities that lack a stored object. It also includes corresponding tests and added translation for the error message in French.

src/Bundle/ChillMainBundle/Workflow/EntityWorkflowManager.php

@@ -61,6 +61,25 @@ class EntityWorkflowManager
         return null;
     }
 
+    /**
+     * Return true if the entityWorkflow may associate a stored object.
+     *
+     * Take care that, for various reasons, the method @see{getAssociatedStoredObject} may return null if, for
+     * various reasons, the associated stored object may not be retrieved.
+     *
+     * @return bool return true if the entityWorkflow may associate a stored object
+     */
+    public function canAssociateStoredObject(EntityWorkflow $entityWorkflow): bool
+    {
+        foreach ($this->handlers as $handler) {
+            if ($handler instanceof EntityWorkflowWithStoredObjectHandlerInterface && $handler->supports($entityWorkflow)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     /**
      * @return list<EntityWorkflow>
      */