CA testing hacks, external failure message, sitl tuning, disabling of rate controller saturation

Signed-off-by: Silvan Fuhrer <silvan@auterion.com>

msg/CMakeLists.txt

@@ -93,6 +93,7 @@ set(msg_files
 	Event.msg
 	FigureEightStatus.msg
 	FailsafeFlags.msg
+	FailureDetectorExtServo.msg
 	FailureDetectorStatus.msg
 	FlightPhaseEstimation.msg
 	FollowTarget.msg

msg/FailureDetectorExtServo.msg

@@ -0,0 +1,5 @@
+uint64 timestamp                    # time since system start (microseconds)
+
+bool fd_servo
+
+uint16 servo_failure_mask           # Bit-mask with servo indices, indicating critical servo failures

msg/FailureDetectorStatus.msg

@@ -14,3 +14,5 @@ bool fd_servo
 float32 imbalanced_prop_metric      # Metric of the imbalanced propeller check (low-passed)
 uint16 motor_failure_mask           # Bit-mask with motor indices, indicating critical motor failures
 uint16 servo_failure_mask           # Bit-mask with servo indices, indicating critical servo failures
+
+uint16 servo_to_center_mask	    # HACK to test allocation without some servos