Add missing const qualifier with clang-tidy fixes

include/animation.h

include/aviFileWriter.h

include/backgroundFilter.h

include/control.h

include/coordItem.h

include/extrCalibration.h

include/filter.h

include/gridItem.h

include/logoItem.h

include/petrack.h

include/player.h

include/stereoContext.h

src/animation.cpp

src/aviFileWriter.cpp

src/backgroundFilter.cpp

src/control.cpp

src/filter.cpp

src/petrack.cpp

src/player.cpp