Improve existing unit tests coverage for O1 Agent's NBI package and implement
new unit tests for SBI and main packages.
Fix also few missing nil value checks found from the source code.
Signed-off-by: Timo Tietavainen <timo.tietavainen@nokia.com>
Change-Id: I3bd0cc1193730960e0bbfe8a7563a167edf4df8f