Function create_server 

pub async fn create_server(
    config: Config,
    manager: Arc<CredentialManager>,
    adapter_manager: Arc<AdapterInstanceManager>,
    backend_manager: Arc<ExternalBackendManager>,
) -> Result<(Arc<AppState>, Pin<Box<dyn Future<Output = Result<()>> + Send>>)>

Create the server and return the state + a future to run