Enable `globalGroup` for KaTeX (or make the global macros configurable)

[uniwuni]

Describe feature

see https://katex.org/docs/options.html:
globalGroup enables to define latex macros that persist throughout formulas.
Because of the note inclusion feature, this allows for latex preambles that can be reused throughout notes.

Additional Information

To implement this, it should be sufficient to change all renderMathInElement-calls, though this might present some issues in macro definitions bleeding through files. In that case, modifying the macros option for KaTeX should be made possible, either in global application options or as an note attribute.