Match the label of nested citation in the math block
CITATION FORMAT :
with only 1 \ref{} in any location between $$, should have at least closed {} pairs
Parameters
citation: string
inline-math citation content without $$
prefix: string|null = null
Returns {content:string;label:string}|null
label or null if not match or bracket not closed correctly
Match the label of nested citation in the math block CITATION FORMAT : with only 1 \ref{} in any location between $$, should have at least closed {} pairs