Getting rid of phonon_static_energy_maker, combining Relaxation steps from phonon and rattling part

`phonon_static_energy_maker` is not required in the phonon workflow. We could set it to None by default. Only when free energies plus total DFT energies are compared, the `phonon_static_energy_maker` might be useful.

Addtionally, there are two optimization steps if rattled and single-displaced data generation is switched on. This might be combined in cases when both options are used.