* Use SafeFile for atomic file writing (with xor checksum readback)
* Write db.proto last because it could be the largest file on the FS (and less critical)
* Don't keep a tmp file around while writing db.proto (because too big to fit two files in the filesystem)
* generate a new critial fault if we encounter errors writing to flash
either CriticalErrorCode_FLASH_CORRUPTION_RECOVERABLE or CriticalErrorCode_FLASH_CORRUPTION_UNRECOVERABLE
(depending on if the second write attempt worked)
* reformat the filesystem if we detect it is corrupted (then rewrite our config files) (only on nrf52 - not sure
yet if we should bother on ESP32)
* If we have to format the FS, make sure to preserve the oem.proto if it exists
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
