Add cleanup action: "Make LaTeX ready: Escape $"

Problem:

1. Want to prepare entries to be used with LaTeX
2. Want to not start math-mode, but instead simply render $ character in my bibliography

Describe the solution you’d like

• Add cleanup action that adds a backslash in front of $
• Name this cleanup action: Make LaTeX ready: Escape $
• Add to the documentation: Adds backslash to $ characters. \$ will be rendered by LaTeX as $ instead of starting math-mode. Do not use this cleanup action, if you have entries that require usage of LaTeX math-mode.

Additional context

• Why not add this function to Make LaTeX ready: Cleanup or Make LaTeX ready: Unicode to LaTeX? Both allow the usage of math-mode, which is fine. This seems to be a zero-sum game and there is no heuristic that can find out if the user wants to use math-mode or simply render the $.

Related to https://github.com/JabRef/jabref/issues/8490#issuecomment-1091209909 and #8650

[Siedlerchr]

@fly-ing-fish No need to adapt the latex <> unicode conversion map. See the existing LatexCleanupFormatter with the regex pattern for ESCAPE_PERCENT_SIGN_ONCE that also works when the value is already escaped.

@ThiloteE For unicode <-> latex it’s kind of both. We use https://github.com/plurimath/unicode2latex

[ThiloteE]

I finished my tests. Here my test library: test-8673-encoding of special characters.bib.txt

I wrote some comments into this file.

Most interesting results:

• entries with citationkeys test1ca and test1cb show that %, $, _, # and & all do not get backslashed when using the Unicode to LaTeX cleanup action. We know the $ is because of math-mode. I wonder why the others are not converted…
• ... does not get converted from Unicode to LaTeX.
• _ seems to be a special case. \_ does also not get converted back via LaTeX to Unicode cleanup action.

Will try to compile the rest of the symbols with Latex one of these days and see what happens