feat(profile): enforce uniqueness of national_code across user profiles and update related error handling

src/UserProfile/Repository/UserProfileRepository.php

@@ -24,6 +24,11 @@ class UserProfileRepository extends ServiceEntityRepository
         return $this->findOneBy(['uuid' => $uuid]);
     }
 
+    public function findOneByNationalCode(string $nationalCode): ?UserProfile
+    {
+        return $this->findOneBy(['nationalCode' => $nationalCode]);
+    }
+
     public function save(UserProfile $profile, bool $flush = true): void
     {
         $this->getEntityManager()->persist($profile);