More refactor in navigator.getCitation()
More refactor in navigator.getCitation()

Makes the function public and taking a callback, that way we can use it
elsewhere as well.

alpheios-project/arethusa,PonteIneptique/arethusa,Masoumeh/arethusa,fbaumgardt/arethusa,Masoumeh/arethusa,fbaumgardt/arethusa,latin-language-toolkit/arethusa,latin-language-toolkit/arethusa,alpheios-project/arethusa,PonteIneptique/arethusa,alpheios-project/arethusa,fbaumgardt/arethusa