[Boardcore] Create namespace 'Boardcore'

src/entrypoints/bmx160-calibration-entry.cpp

src/entrypoints/config-dsgamma.cpp

src/entrypoints/sdcard-benchmark.cpp

src/shared/ActiveObject.h

src/shared/Constants.h

src/shared/Debug.cpp

src/shared/Debug.h

src/shared/Singleton.h

src/shared/TimestampTimer.cpp

src/shared/TimestampTimer.h

src/shared/diagnostic/CpuMeter.cpp

src/shared/diagnostic/CpuMeter.h

src/shared/diagnostic/FaultCounter.h

src/shared/diagnostic/FaultCounterData.h

src/shared/diagnostic/LogSink.h

src/shared/diagnostic/PrintLogger.cpp

src/shared/diagnostic/PrintLogger.h

src/shared/diagnostic/PrintLoggerData.h

src/shared/diagnostic/SkywardStack.h

src/shared/diagnostic/StackData.h