tests: fs: nvs: unittest with corrupted sector close op
tests: fs: nvs: unittest with corrupted sector close op

Added a test case with corner case scenario, in which sector closing
operation is interrupted (e. g. due to power-down).

Signed-off-by: Kamil Piszczek <94a00d4c21e2b5f86e16c4df4b1ac94e543626d8@nordicsemi.no>

nashif/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,galak/zephyr,galak/zephyr,nashif/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,finikorg/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,galak/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,nashif/zephyr,finikorg/zephyr