New status code for two SMP authorization failures

On BTA_DM_AUTH_SMP_UNKNOWN_ERR and BTA_DM_AUTH_SMP_CONN_TOUT, bond state
status will be notified as BT_STATUS_AUTH_FAILURE.  This is observed during
the pairing flow with iOS devices.

Plus minor cleanup on SMP errors and fail reasons.

Bug: 29779689
Change-Id: Ia32fe6bb84b07272d5159409f65217a06a2e5f8e