feat: more complete set of gnss data and flexibility #862
Description
there are some fields in common gps messages (GGA, RMC) that dont seem to be available from lisp scripts. I am most interested in Track made good in RMC that is basically the direction of travel. But also number of satellites is important. Eventually it would be nice to be able to add additional message types, maybe through lisp so they dont take up flash space unless necessary. Namely I have a UM982 which is a dual antenna receiver thus can give a rock solid heading data without compasses and worrying about motor interference. for this it sends a custom GNTHS message. I have also found some others like the cheaper non-RTK LC29HEA which uses a whole different message: PQTMTAR. So it seems like new message types should be dynamically registered via lisp/package rather than trying to support every single variant under the sun.
To give a bigger picture I am hoping to make some semiautonomous/autonomous water surface rovers (think rc boat with a special fishlike propulsion) and if I can run everything off of a VESC+VESC express that would be extremely convenient (we want to get it super small and cheap)