- Introduced NVS configuration options in Kconfig.
- Implemented NVS initialization and deinitialization in relay_chn_core.
- Added functions for storing and retrieving relay channel direction and tilt sensitivity in NVS.
- Updated relay_chn_tilt and relay_chn_output to utilize NVS for state management.
- Created relay_chn_nvs.c and relay_chn_nvs.h for NVS-related functionalities.
Closes #1074.