Add support for GPS location in log files

[brentru]

For Offline Mode, we can implement this without touching IO (yet)!

• Add GPS module's timestamp (Allow GPS Breakouts to timestamp the log file #698 ) and location fix to the JSONL log line

Requires: adafruit/Wippersnapper_Protobuf#118

[brentru]

Should implement UART first and then AQ sensors and then GPS, as GPS modules would require that as a prerequisite.

#639