Add signature functionality to workflow entities

Created new files to add signature functionality to the workflow entities, including signature state enums and signature metadata. Added these changes to the migration script as well. Updated EntityWorkflowStep to include a collection for signatures.

src/Bundle/ChillMainBundle/Repository/Workflow/EntityWorkflowStepSignatureRepository.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\MainBundle\Repository\Workflow;
+
+use Chill\MainBundle\Entity\Workflow\EntityWorkflowStepSignature;
+use Doctrine\ORM\EntityManagerInterface;
+use Doctrine\Persistence\ObjectRepository;
+
+/**
+ * @template-implements ObjectRepository<EntityWorkflowStepSignature>
+ */
+class EntityWorkflowStepSignatureRepository implements ObjectRepository
+{
+    private \Doctrine\ORM\EntityRepository $repository;
+
+    public function __construct(EntityManagerInterface $entityManager)
+    {
+        $this->repository = $entityManager->getRepository(EntityWorkflowStepSignature::class);
+    }
+
+    public function find($id): ?EntityWorkflowStepSignature
+    {
+        return $this->repository->find($id);
+    }
+
+    public function findAll(): array
+    {
+        return $this->repository->findAll();
+    }
+
+    public function findBy(array $criteria, ?array $orderBy = null, ?int $limit = null, ?int $offset = null): array
+    {
+        return $this->findBy($criteria, $orderBy, $limit, $offset);
+    }
+
+    public function findOneBy(array $criteria): ?EntityWorkflowStepSignature
+    {
+        return $this->findOneBy($criteria);
+    }
+
+    public function getClassName(): string
+    {
+        return EntityWorkflowStepSignature::class;
+    }
+}