[i71f] rename axis classes -> Histo|DiscreteAxis ()

Base/Axis/DiscreteAxis.cpp

Base/Axis/DiscreteAxis.h

Base/Axis/HistoAxis.cpp

Base/Axis/HistoAxis.h

Device/Coord/CoordSystem1D.cpp

Device/IO/DataFormatUtils.cpp

Device/IO/ReadReflectometry.cpp

GUI/Model/Device/GrazingScanItem.cpp

GUI/Model/Device/GrazingScanItem.h

GUI/Model/Device/PointwiseAxisItem.cpp

GUI/Model/Device/SourceItems.cpp

GUI/View/Instrument/AlphaScanEditor.cpp

GUI/View/Loaders/QREDataLoader.cpp

Sim/Export/PyFmt2.cpp

Sim/Scan/AlphaScan.cpp

Sim/Scan/QzScan.cpp

Tests/ReferenceData/ExamplesMini/ff/Bipyramid4.0.int.gz

Tests/ReferenceData/ExamplesMini/ff/Bipyramid4.1.int.gz

Tests/ReferenceData/ExamplesMini/ff/Bipyramid4.2.int.gz

Tests/ReferenceData/ExamplesMini/ff/Box.0.int.gz