Refactor subject conversion handling and enhance audit logging

- Replaced `Subject|array` return types with `SubjectBag` in `SubjectConverterInterface` for more robust handling.
- Updated `getSubjectsForEntity` to include an optional `$includeAssociated` parameter for finer control over associated subject resolution.
- Refactored `AuditEvent` to differentiate `mainSubject` from associated subjects, improving clarity in audit logging.
- Introduced database schema changes to add `main_subject` and `subjects` columns in the `chill_main_audit_trail` table.
- Added `SubjectBag` class for grouped subject management and implemented deduplication logic.
- Updated all converters and test cases to use the new `SubjectBag` approach, ensuring compatibility.
- Improved event dispatching in controllers to utilize the updated `AuditEvent` structure and refined metadata handling.

src/Bundle/ChillPersonBundle/Controller/PersonController.php

@@ -206,7 +206,7 @@ final class PersonController extends AbstractController
             'You are not allowed to see this person.'
         );
 
-        $this->eventDispatcher->dispatch(new AuditEvent(AuditTrail::AUDIT_VIEW, [$person]));
+        $this->eventDispatcher->dispatch(new AuditEvent(AuditTrail::AUDIT_VIEW, $person));
 
         return $this->render(
             '@ChillPerson/Person/view.html.twig',