Support for booting over private failsafety interface

Currently, despite of being able to use private failsafety interfaces, the boot procedure for starting database node depends on the first private network interface. It is planned to allow the booting also from private failsafety interfaces.

As a workaround, to achieve this functionality in the current version, one can switch the MAC addresses for the private interface and the private failsafety interface via EXAoperation.