using mocap with px4

vision_pose/pose and local_position/pose should be the same value

use EKF2 and vision_pose/pose

parameters related to EKF2

- SYS\_MC\_EST\_GROUP = ekf2
- EKF2\_AID\_MASK = 24 (enable vision position fusion and vision yaw fusion)
- EKF2\_BARO\_GATE = 0 (disable barometer)
- EKF2\_EVP\_NOISE = 0.01 (to trust mocap more)
- EKF2\_EV\_GATE = 500 (accept any mocap info, don’t reject)
- EKF2\_HGT\_MODE = vision (use vision for altitude estimation)
- GPS\_P\_GATE   set to large value 

note that the parameters need to be reset to default if not using mocap