Dual GNSS antenna base length and slave down measurement

[dragonfly771]

Is your feature request related to a problem? Please describe.
Currently there is no option available to measure the GNSS antenna base length and slave down directly in the frontend. Up to now the only option is to measure these values by hand or use the sensor.readings file on the SD card + use XCSoar NMEA monitor.

Describe the solution you'd like
In the Sensor Box setup menu there should be an additional feature to measure and update the GNSS antenna base length ans slave down value. Only the slave right value needs to be measured and set manually.

Describe alternatives you've considered
The other option would be to include the display of these values in the info display. Then the user can not the values and manually input them in the init settings.

Additional context
This would improve the setup process significantly for users which use the Larus as standalone vario, without a flight computer.

[Simsys]

To develop a solution for this, support from the sensor firmware is required. It must also be determined whether the data in question should always be captured automatically or whether the remaining data should be entered manually. The interface must be documented. Once this is done, the front-end support can be implemented.

see larus-breeze/sw_sensor#213

[realtimepeople]

The reporting of the required values is now implemented in sensor version 0.7.2.5
It is desirable to display those values in the test page.

[Simsys]

Before implementation on the display

1. We need a specification of the CAN telegrams here.
   https://github.com/larus-breeze/doc_larus

2. The Flightplayer should be expanded accordingly
   https://github.com/larus-breeze/sw_tools/tree/master/flight_player

3. In addition, sample recording files would be very helpful for testing

[Simsys]

I think we need a bit more time to finalise this: Target version v0.4.2

[dragonfly771]

That´s still an important topic for the initial installation of the Larus sensor.