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/ChillMainBundle/Audit/SubjectConverterManagerInterface.php

@@ -13,8 +13,5 @@ namespace Chill\MainBundle\Audit;
 
 interface SubjectConverterManagerInterface
 {
-    /**
-     * @return list<Subject>
-     */
-    public function getSubjectsForEntity(mixed $subject): array;
+    public function getSubjectsForEntity(object $subject, bool $includeAssociated = false): SubjectBag;
 }