Add NVS mode option to enum gps_driver_mode_t
Add header files for nvs and NVS support (inicalization, 'try switch')
Add nvs header file and nvs.cpp file to makefile
Add nvs.cpp file
clear erros
set_baudrate function set/clear some parameters uart configuration paramaters but NVS needs odd parity so after set_baudrate function this parameters are rewrited to work with NVS
correct configuration for NVS uart port
correct error message