apply accel/gyro scaling and fix axes directions

[vidma]

with IMU_ALIGN_CW0:

• gyro: rotations in pahrs are legit now (positive is: roll right (X), pitch up (Y), yaw right (Z))

# yaw right
roll:+7.6       pitch:+1.6      yaw:+46.9
# pitch down
roll:-2.8       pitch:-62.5     yaw:+15.7
# roll left
roll:-35.4      pitch:-12.2     yaw:+6.0

• pacc (ax and ay looks fishy?)

# pacc:      Filtered accelerometer (expected: -2 to 2; x,y 0 when level, z 1 when level)
#     // x=North (forward), y=East (right), z=Down 
#    // acc: gravitation force is positive in axis direction

# az: level: OK
ax:+0.02        ay:+0.18        az:+0.98
# acc up: OK
ax:-0.43        ay:+0.57        az:+2.67

# ax: forward rotated to ground
ax:+1.02        ay:+0.04        az:-0.44

# ay: east/right rotated to ground
ax:+0.13        ay:+1.00        az:+0.09


# ax: move forward and break
ax:-0.06        ay:+0.17        az:+1.09
ax:-1.34        ay:+0.21        az:+1.53
ax:-1.56        ay:+0.68        az:-0.95
ax:+1.64        ay:+0.09        az:+2.26
ax:+0.69        ay:+0.13        az:+0.29
ax:+0.12        ay:+0.42        az:+0.89

# ay: move to the left and break
# y=East (right), acc: gravitation force is positive in axis direction 
ax:+0.08        ay:+0.29        az:+0.92
ax:-0.42        ay:+2.51        az:+1.06
ax:+1.37        ay:+0.05        az:+0.76

[vidma]

@qqqlab