Decoding for EmberStatus, the 1-byte status code returned by most EZSP
commands and carried in stackStatusHandler callbacks.
Only the codes relevant to the bring-up / network path are named; anything
else decodes to {:unknown, byte} so nothing is silently swallowed.
Summary
Functions
Decode a single EmberStatus byte to a friendly atom.
True if the status byte is EMBER_SUCCESS (0x00).