Highlight available citations in the PDF

[Futur3r]

Is your feature request related to a problem? Please describe.
It is hard to verify if all citations in a PDF have been contributed in Wikidata.
The user need to compare the PDF with the citations in the citations panel one by one.

Describe the solution you'd like
I don't know if it's feasible, but ...

The citations title in the PDF would be highlighted, if the corresponding citation exist in the citations panel.

To do that, when the PDF reader opens, cita would find in the PDF text every title of its citations items.
And if a whole title string match character for character (like a Ctrl+F), it would highlight it (in green, for example).

So the user would know which citation is missing in the citation panel just by looking at the references of a PDF article.