2次元構造格子を出力する。
call cg_iric_write_grid2d_coords_withgridid(fid, nx, ny, x, y, gid, ier)
ier = cg_iRIC_Write_Grid2d_Coords_WithGridId(fid, nx, ny, x, y, gid);
gid = cg_iRIC_Write_Grid2d_Coords_WithGridId(fid, nx, ny, x, y)