Add check to openmc_cell_set_temperature to not exceed nuclear data bounds

[aprilnovak]

1. Add check to ensure that a temperature outside the available cross section temperatures (for each nuclide in the cell's material) is not set; if the temperature exceeds the available data, set it to the extremum.

2. Add check to ensure that the temperature of a cell filled with another universe isn't changed - this routine should only work for cells filled with a homogeneous material