Refactor PersonCreate flow to introduce PersonCreateDTO

- Replaced `Person` entity binding with `PersonCreateDTO` in `CreationPersonType` to enable better data handling.
- Added `PersonCreateDTOFactory` for creating and mapping `PersonCreateDTO` instances.
- Extracted `newAction` logic into `PersonCreateController` for clearer separation of responsibilities.
- Updated `PersonIdentifiersDataMapper` and `PersonIdentifierWorker` to support default identifier values.
- Adjusted related services, configurations, and templates accordingly.

src/Bundle/ChillPersonBundle/PersonIdentifier/Identifier/StringIdentifier.php

@@ -70,4 +70,9 @@ final readonly class StringIdentifier implements PersonIdentifierEngineInterface
 
         return $violations;
     }
+
+    public function getDefaultValue(PersonIdentifierDefinition $definition): array
+    {
+        return ['content' => ''];
+    }
 }