[skip-ci] better names for doxygen macros. (#8168)

documentation/doxygen/MakeRCanvasJS.C

documentation/doxygen/MakeTCanvasJS.C

documentation/doxygen/filter.cxx

tutorials/graphics/arrows.C

tutorials/graphics/mandelbrot.C

tutorials/v7/box.cxx

tutorials/v7/draw.cxx

tutorials/v7/draw_axes.cxx

tutorials/v7/draw_frame.cxx

tutorials/v7/draw_legend.cxx

tutorials/v7/draw_pave.cxx

tutorials/v7/draw_rh1.cxx

tutorials/v7/draw_rh2.cxx

tutorials/v7/draw_rh2_colz.cxx

tutorials/v7/draw_rh2_large.cxx

tutorials/v7/draw_rh3.cxx

tutorials/v7/draw_rh3_large.cxx

tutorials/v7/draw_subpads.cxx

tutorials/v7/draw_text.cxx

tutorials/v7/draw_v6.cxx