Rework superscript: latex-to-unicode and unicode-to-latex roundtrip not working

[koppor]

Bib entry:

@InProceedings{NvLKL2007,
  author    = {J{\"o}rg Nitzsche and Tammo van Lessen and Dimka Karastoyanova and Frank Leymann},
  title     = {{BPEL}\textsuperscript{light}},
  booktitle = {Proceedings 5\textsuperscript{th} International Conference on Business Process Management (BPM)},
}

latex to unicode:

@InProceedings{NvLKL2007,
  author    = {Jörg Nitzsche and Tammo van Lessen and Dimka Karastoyanova and Frank Leymann},
  title     = {BPELˡⁱᵍʰᵗ},
  booktitle = {Proceedings 5ᵗʰ International Conference on Business Process Management (BPM)},
}

We once had the discussion somewhere (I don't remember where), that Unicode superscripts should be used for math only. This is also stated there: https://en.wikipedia.org/wiki/Unicode_subscripts_and_superscripts

The issue with the current conversion is that unicode-to-latex does not revert that conversion:

@InProceedings{NvLKL2007,
  author    = {J{\"{o}}rg Nitzsche and Tammo van Lessen and Dimka Karastoyanova and Frank Leymann},
  title     = {BPELˡⁱᵍʰᵗ},
  booktitle = {Proceedings 5ᵗʰ International Conference on Business Process Management (BPM)},
}

I propose to NOT convert superscript to unicode at all in the latex-to-unicode converter. For the entry table, this conversion is fine with me as it improves the readability. Maybe, we have to parameterize our latex-to-unicode converter?

With this issue, I cannot recommend to use biblatex and our default conversion settings anymore as it is not possible to go back to bibtex for papers (Springer's LNCS, ...) anymore.

Refs #2601

[ThiloteE]

@koppor Is this still relevant?
What IF Unicode2LaTeX were able to convert this back to LaTeX, is this something that should be done or will this create problems? Should we ask plurimath to include this in their conversion or should this also be included in the LaTeX2UnicodeawareLaTeX converter?

[Siedlerchr]

Refs #8639
Unicode2Latex is NOT handled by the latex2unicode library