Freset: properly reset graphics objects (bug #35511) * graphics.in.h (base_graphics_object, graphics_object, root): add new method "get_factory_defaults_list" to retrieve factory defaults as property_list * graphics.in.h (base_graphics_object::reset_default_properties (void)): move definition to graphics.cc * graphics.cc (xreset_default_properties): new function to set a list of prop/val * graphics.cc (base_graphics_object::reset_default_properties): use xreset_default_properties, override with parents' defaults * graphics.cc (root_figure::reset_default_properties, figure::reset_default_properties, uitoolbar::reset_default_properties): same as above but first empty local defaults * graphics.cc (axes_figure::reset_default_properties): same as above but use "propeties.set_defaults" to reset properties to their factory value. * graphics.cc (axes_figure::properties::set_defaults): new "reset" mode, that does the same as "replace" but x/y/zlabels and title are reset instead of being deleting/recreating. * graphics.cc: add %!tests for Freset

#include <iostream>
#include <octave/oct.h>

int
main (void)
{
  std::cout << "Hello Octave world!\n";

  int n = 2;
  Matrix a_matrix = Matrix (n, n);

  for (octave_idx_type i = 0; i < n; i++)
    for (octave_idx_type j = 0; j < n; j++)
      a_matrix(i,j) = (i + 1) * 10 + (j + 1);

  std::cout << a_matrix;

  return 0;
}