DDS: Vehicle to report SITL state

[tizianofiorenzani]

ROS visualization and integration with other sensors require the vehicle's actual state rather than the estimated one, especially if we are using cameras or lidars as a measurement for estimating the state itself.

Feature request

A new publisher /ap/sim/groundtruth with a custom message type, published at at least 50Hz in SITL only.

The message could be like:

std_msgs/Header header

# Geographic position
float64 latitude    # degrees
float64 longitude   # degrees
float64 altitude    # meters above mean sea level

# Cartesian position in ENU frame relative to home position
geometry_msgs/Vector3 position

# Orientation quaternion in ENU frame
geometry_msgs/Quaternion orientation

# Linear velocity in ENU frame (m/s)
geometry_msgs/Vector3 linear_velocity

# Angular velocity in body frame (rad/s)
geometry_msgs/Vector3 angular_velocity

Platform
[ x ] All
[ ] AntennaTracker
[ ] Copter
[ ] Plane
[ ] Rover
[ ] Submarine

[OmkarSarkar204]

HI! @tizianofiorenzani ,I'd like to work on this, ill open a PR shortly.