[#3111] fix markdown rendering applying before mathjax rendering

[AndreaBarbasso]

References

• Fixes #3111

Description

With this PR, LaTeX formulas are rendered with mathjax before any markdown rendering is applied. This fixes unwanted behaviors described on the linked issue.

Instructions for Reviewers

List of changes in this PR:

• Applied mathjax rendering before markdown rendering (if mathjax is enabled);
• Removed nativeWindow injection in client-math.service (since it's a Client-Side-Rendering service, there is no need to use the injection);
• Included the popular LaTeX $$ delimiter in the list of approved delimiters.

To test this PR, try to use this text in any place where the markdown rendering is enabled: ...measurements in (EDT-TTF-CONH$_2$)$_2^{+}$[BABCO$^{-}$] (EDT-BCO) confirmed the absence.... It should render fine, instead of showing a broken formula and some italic text.

Checklist

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• [x] If my PR fixes an issue ticket, I've linked them together.