Servo control message
# Servo control message
uint32 MESSAGE_VERSION = 0
uint64 timestamp # time since system start (microseconds)
uint64 timestamp_sample # the timestamp the data this control response is based on was sampled
uint8 NUM_CONTROLS = 8
float32[8] control # range: [-1, 1], where 1 means maximum positive position,
# -1 maximum negative,
# and NaN maps to disarmed