camera_trigger.msg: add feedback field to understand if message camera from...

camera_trigger.msg: add feedback field to understand if message camera from trigger or capture driver

msg/camera_trigger.msg

@@ -2,3 +2,4 @@ uint64 timestamp	# time since system start (microseconds)
 uint64 timestamp_utc # UTC timestamp
 
 uint32 seq		# Image sequence number
+bool feedback	# Trigger feedback from camera

src/drivers/camera_capture/camera_capture.cpp

@@ -104,6 +104,7 @@ CameraCapture::capture_callback(uint32_t chan_index,
 		}
 
 		trigger.seq = _capture_seq++;
+		trigger.feedback = true;
 
 		if (_camera_capture_feedback) {
 			orb_publish(ORB_ID(camera_trigger), _trigger_pub, &trigger);

src/drivers/camera_trigger/camera_trigger.cpp

@@ -768,6 +768,7 @@ CameraTrigger::engage(void *arg)
 	trigger.timestamp_utc = (uint64_t) tv.tv_sec * 1000000 + tv.tv_nsec / 1000;
 
 	trigger.seq = trig->_trigger_seq;
+	trigger.feedback = false;
 
 	orb_publish(ORB_ID(camera_trigger), trig->_trigger_pub, &trigger);