uorb_to_ros_msgs: delete all messages on the out dir first, so it can also consider message deletions on the input dir

 - <cinttypes> isn't available in the NuttX c++ library

- Use the values from landing_gear.msg

- landing_gear: refactor state name
- Add the keep state to the landing gear message
- Adapt FlightTaskManual, FlightTaskAutoMapper, mc_pos_control,
to review message definition

- An new message is created just for the landing gear
- The old logic is repalaced by publishing this new topic

* attitude and rate setpoint message: use 3D array for thrust demand
* FixedWingAttitudeControl: rework airspeed scaling
  * move airspeed and scaling calculation into separate method
  * if vtol in hover and airspeed disabled use minimum airspeed instead of trim airspeed

- move the update after the integration: a new computed jerk has an impact at the next epoch only
- add jerk reduction in case of too large integration time: when a jerk of "min_jerk" during dt is too much
- add jerk reduction if the integration time is larger than the predicted one and that integrating that jerk would lead to an acceleration overshoot
- rename some variables

obstacle_distance: update distances description according to latest obstacle_distance mavlink message