Use new PositionSource class
This moves the position source job to kirogi, since vehicles will need to receive position information, and different position sources can be used, like:
- RTK
- Remote RTK
- External GPS
- NMEA position source
- etc
It makes more sense to have a C++ class now to make it possible and available for the plugin structure to access such information.
This is the first version that replaces the actual implementation with the new class.