msg ROS2 compatibility, microdds_client improvements (timesync, reduced code size, added topics, etc), fastrtps purge

- update all msgs to be directly compatible with ROS2
 - microdds_client improvements
   - timesync
   - reduced code size
   - add to most default builds if we can afford it
   - lots of other little changes
 - purge fastrtps (I tried to save this multiple times, but kept hitting roadblocks)

msg/VehicleGlobalPosition.msg

@@ -0,0 +1,29 @@
+# Fused global position in WGS84.
+# This struct contains global position estimation. It is not the raw GPS
+# measurement (@see vehicle_gps_position). This topic is usually published by the position
+# estimator, which will take more sources of information into account than just GPS,
+# e.g. control inputs of the vehicle in a Kalman-filter implementation.
+#
+
+uint64 timestamp		# time since system start (microseconds)
+uint64 timestamp_sample         # the timestamp of the raw data (microseconds)
+
+float64 lat			# Latitude, (degrees)
+float64 lon			# Longitude, (degrees)
+float32 alt			# Altitude AMSL, (meters)
+float32 alt_ellipsoid		# Altitude above ellipsoid, (meters)
+
+float32 delta_alt 	# Reset delta for altitude
+uint8 lat_lon_reset_counter	# Counter for reset events on horizontal position coordinates
+uint8 alt_reset_counter 	# Counter for reset events on altitude
+
+float32 eph			# Standard deviation of horizontal position error, (metres)
+float32 epv			# Standard deviation of vertical position error, (metres)
+
+float32 terrain_alt		# Terrain altitude WGS84, (metres)
+bool terrain_alt_valid		# Terrain altitude estimate is valid
+
+bool dead_reckoning		# True if this position is estimated through dead-reckoning
+
+# TOPICS vehicle_global_position vehicle_global_position_groundtruth
+# TOPICS estimator_global_position