Having a generic interface over the GPS drivers makes dedicated
functionality for each driver harder. Move the Septentrio driver into
its own module under the `gnss` driver directory, and let it have its
own parameters for only the functionality it requires. This also helps
with adding new features because they only need to be implemented for
the driver that wants it, simplifying testing.
- 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)
