Inpgen failure handling

[janssenhenning]

I think it would be useful to introduce some more failure handling into the inpgen calculation.

There are two examples I can think of at the moment, let me know what you think:

• We should maybe introduce a check that looks if the specific atom parameters were transferred correctly this could be done by reextracting the parameter data for the produced FleurinpData and comparing the specified ones. I don't think this should lead to a failure of the Calculations but a clear warning would be nice so that does not have to be discovered manually
• Imprecisions in the bravais matrix and atom positions that lead to barely missing symmetries lead to a message being written out in the inpgen (At the moment this is not even a warning but a normal output with ****Warning**** at the top :D). If we move this to a regular warning we could detect this case easily and either try to correct it using methods to for example symmetrize the bravais matrix in pymatgen, ase or similar or recommend this clearly with a more prominent warning on the aiida side