[CpuMeter] Implemented statistics calulcation with Stats class

src/shared/ActiveObject.h

src/shared/algorithms/NAS/NAS.h

src/shared/diagnostic/CpuMeter.cpp

src/shared/diagnostic/CpuMeter.h

src/tests/logger/test-logger.cpp

src/tests/sensors/calibration/test-calibration-benchmark.cpp

src/tests/sensors/test-l3gd20-fifo.cpp

src/tests/sensors/test-l3gd20.cpp