Expose timeout option for parameter service calls by SyncParametersClient

[dhood]

As an example, SyncParametersClient::set_parameters doesn't take a timeout option. So, if anything goes wrong in the service call (e.g. the server goes down), we will get stuck waiting indefinitely.

Exposing a timout that is set to -1 by default (as is done for SyncParametersClient::wait_for_service) would be appropriate.

Parameter tests in test_rclcpp (e.g. this one) should be updated to specify a timeout, so that the other tests in the file can be run even if one of them hangs.

[wjwwood]

Updated link:

rclcpp/rclcpp/src/rclcpp/parameter_client.cpp

Lines 453 to 468 in 96ebf59

	std::vector<rcl_interfaces::msg::SetParametersResult>
	SyncParametersClient::set_parameters(
	const std::vector<rclcpp::Parameter> & parameters)
	{
	auto f = async_parameters_client_->set_parameters(parameters);
	using rclcpp::executors::spin_node_until_future_complete;
	if (
	spin_node_until_future_complete(
	*executor_, node_base_interface_,
	f) == rclcpp::executor::FutureReturnCode::SUCCESS)
	{
	return f.get();
	}
	return std::vector<rcl_interfaces::msg::SetParametersResult>();
	}

[fujitatomoya]

@wjwwood

thanks for the review, i think we can close this.