Clean up Sensor Data structs

There are some 'dead' member variables in the raw_sensor_data struct. All the accel_ members have been moved into gam, and the lidar data is split between a lidar_t lidar member and a lidar_distance_m member variable. It would be best for code readability to remove the extra variables and move the lidar_distance_m variable into the lidar_t lidar struct.