mc_rate: compute control energy and publish to status msg

msg/CMakeLists.txt

@@ -39,6 +39,7 @@ include(px4_list_make_absolute)
 set(msg_files
 	actuator_armed.msg
 	actuator_controls.msg
+	actuator_controls_status.msg
 	actuator_outputs.msg
 	adc_report.msg
 	airspeed.msg

msg/actuator_controls_status.msg

@@ -0,0 +1,10 @@
+uint64 timestamp			# time since system start (microseconds)
+
+uint8 INDEX_ROLL = 0
+uint8 INDEX_PITCH = 1
+uint8 INDEX_YAW = 2
+uint8 INDEX_THROTTLE = 3
+
+float32[4] control_power
+
+# TOPICS actuator_controls_status actuator_controls_status_0 actuator_controls_status_1