CDB3-5271 Створити окремі ендпоїнти для документів до сутності Cancellation в реєстрі

• GET /api/registry/{execution_type:(executions|large_executions)}/{obj_id}/cancellations/{cancellation_id}/documents/{doc_id}/download

• GET /api/registry/{execution_type:(executions|large_executions)}/{obj_id}/cancellations/{cancellation_id}/documents/{doc_id}

• GET /api/registry/{execution_type:(executions|large_executions)}/{obj_id}/cancellations/{cancellation_id}/documents

• GET /api/registry/{asset_type:(assets|large_assets)}/{obj_id}/cancellations/{cancellation_id}/documents/{doc_id}/download

• GET /api/registry/{asset_type:(assets|large_assets)}/{obj_id}/cancellations/{cancellation_id}/documents/{doc_id}

• GET /api/registry/{asset_type:(assets|large_assets)}/{obj_id}/cancellations/{cancellation_id}/documents