Add testcontainers for integration tests

[korchizhinskiy]

This code about connect new library - https://testcontainers.com/guides/getting-started-with-testcontainers-for-python/

postgres = PostgresContainer("postgres:16-alpine")


@pytest_asyncio.fixture(autouse=True, scope="session")
async def setup_database(request: SubRequest):
    postgres.start()

    def remove_container():
        postgres.stop()

    request.addfinalizer(remove_container)