tempcal: sandbox app for temperature calibration

src/modules/tempcal/CMakeLists.txt

src/modules/tempcal/matrix_alg.cpp

src/modules/tempcal/matrix_alg.h

src/modules/tempcal/polyfit.cpp

src/modules/tempcal/polyfit.h

src/modules/tempcal/tempcal_main.cpp

src/modules/tempcal/tempcal_params.c