Fixes for feature "Regroupment of center"

* allow more than 15 character in regroupment name
* remove unused methods in PickCenterType
* show only active Regroupment in form
* remove dead code and commented code

src/Bundle/ChillMainBundle/Repository/RegroupmentRepository.php

@@ -38,6 +38,11 @@ final class RegroupmentRepository implements ObjectRepository
         return $this->repository->findAll();
     }
 
+    public function findAllActive(): array
+    {
+        return $this->repository->findBy(['isActive' => true], ['name' => 'ASC']);
+    }
+
     /**
      * @param mixed|null $limit
      * @param mixed|null $offset