Improved LibreOffice-JabRef integration

Nowadays, more and more researchers and students choose OpenOffice as an alternative to MS Office. JabRef already provides OpenOffice integration to support reference management, but several important limitations remain: a) JabRef does not properly support footnote citation for CSL style. b) Citations inserted by other reference management tools are not compatible with JabRef. c) Several issues regarding LibreOffice have remained unsolved for years. To address these problems, this project intend to introduce a unified citation representation and a shared global ordering component to ensure consistent behavior across in-text citations, footnotes, and bibliographies. In addition, it enables smoother switching between citation styles and improves compatibility with other reference management tools. Overall, this project will enhance the reliability and usability of JabRef's OpenOffice integration for academic writing.