Move thermalScattering reactions into uncorrelatedCE folder

[ChasingNeutrons]

The thermal scattering reactions are extensions of uncorrelatedCE. Therefore, it would be appropriate for that folder to be inside uncorrelatedCE for ease of navigation.

[ChasingNeutrons]

Furthermore, with inelastic scattering in hydrogen in water in ENDF/B-8, we can produce neutrons at energies slightly below 1E-11MeV. I think we should put a floor inside the inelastic sampling to catch these guys. Or maybe we should kill them?

[ChasingNeutrons]

Closed by #215