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/SensorsStatusImu.msg

@@ -0,0 +1,18 @@
+#
+# Sensor check metrics. This will be zero for a sensor that's primary or unpopulated.
+#
+uint64 timestamp # time since system start (microseconds)
+
+uint32 accel_device_id_primary       # current primary accel device id for reference
+
+uint32[4] accel_device_ids
+float32[4] accel_inconsistency_m_s_s # magnitude of acceleration difference between IMU instance and mean in m/s^2.
+bool[4] accel_healthy
+uint8[4] accel_priority
+
+uint32 gyro_device_id_primary       # current primary gyro device id for reference
+
+uint32[4] gyro_device_ids
+float32[4] gyro_inconsistency_rad_s # magnitude of angular rate difference between IMU instance and mean in (rad/s).
+bool[4] gyro_healthy
+uint8[4] gyro_priority