Use Ionization energies from quantum defect papers

[johannes-moegerle]

Since we now also use NIST energies for low lying states, the ionization energy is not just a global energy shift anymore and we should take care how NIST energies and energies from the quantum defects match together.
For this we probably need to use the ionization energies of the papers from the quantum defects and not just some ionization energy (e.g. from NIST) like we currently do.
However, it also seems like this in the most cases is only a small shift ....

Also use the corrected Rydberg constants from the corresponding paper

[johannes-moegerle]

or just always use NIST data from here: https://physics.nist.gov/PhysRefData/ASD/ionEnergy.html
currently we mostly use data from e.g. here https://webbook.nist.gov/cgi/inchi?ID=C7440235&Mask=20 (which however seems not as up to date as NIST) or from individual papers