Include graphics objects with hidden handles in axes limit calculation (bug #63095). * libinterp/corefcn/graphics.cc (get_children_limits): Get handles to all axes children including those with hidden handle visibility. Add BIST. * libinterp/corefcn/graphics.in.h (text::update_position): Do not automatically change "zliminclude" property. Axes labels are implemented as text objects, and we don't want their extent to be included in the axis limit calculation.

%!test
%! s = rand (3, 4, "single");
%! sc = s + i * rand (3, 4, "single");
%! d = rand (3, 4, "double");
%! dc = d + i * rand (3, 4, "double");
%!
%! [sx, scx, dx, dcx] = mexnumtst (s, sc, d, dc);
%! assert (s, sx)
%! assert (sc, scx)
%! assert (d, dx)
%! assert (dc, dcx)