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/Subject.php

@@ -25,4 +25,26 @@ class Subject
     {
         return [...$this->identifiers, 't' => $this->type];
     }
+
+    public function isEqual(Subject $subject): bool
+    {
+        if ($subject->type !== $this->type) {
+            return false;
+        }
+
+        foreach ($this->identifiers as $k => $identifierValue) {
+            if (!array_key_exists($k, $subject->identifiers)) {
+                return false;
+            }
+            if ($subject->identifiers[$k] !== $identifierValue) {
+                return false;
+            }
+        }
+
+        if (count($this->identifiers) !== count($subject->identifiers)) {
+            return false;
+        }
+
+        return true;
+    }
 }