attitude setpoint topic: cleanup of matrix class usage

src/drivers/bst/bst.cpp

src/drivers/vmount/output.cpp

...es/attitude_estimator_ekf/attitude_estimator_ekf_main.cpp

...ples/ekf_att_pos_estimator/ekf_att_pos_estimator_main.cpp

src/examples/fixedwing_control/main.cpp

src/examples/rover_steering_control/main.cpp

src/modules/commander/accelerometer_calibration.cpp

src/modules/commander/commander.cpp

src/modules/local_position_estimator/sensors/flow.cpp

.../position_estimator_inav/position_estimator_inav_main.cpp