Closes #12484

Reworked CSL reference mark sorting to build partition-aware range entries and remap footnote citations to their footnote markers before ordering, ensuring numbering reflects footnote placement.

Added comparison logic that uses in-text ordering when possible and falls back to partition indices so citations within the same footnote keep their textual sequence

Steps to test

####Automated verification

1. Ensure you have a working Java and LibreOffice development environment (Java 17+, LibreOffice SDK).
2. From the repository root, run the OpenOffice/LibreOffice integration checks: ./gradlew :jablib:check
3. If you only want to exercise the relevant logic, you can narrow it down with ./gradlew :jablib:test --tests org.jabref.logic.openoffice.oocsltext.CSLReferenceMarkManagerTest.

####Manual verification in LibreOffice

1. Build the LibreOffice extension: ./gradlew :jablib:assemble.
2. Install the freshly built extension (jablib/build/libs/JabRef-OpenOffice-integration.oxt) into LibreOffice.
3. Open a document that mixes in-text citations and footnote citations, using a numeric CSL style.
4. Insert several citation groups in the body text and multiple citations inside one or more footnotes.
5. Trigger “Update citation numbers” from the JabRef LibreOffice plugin.

Mandatory checks

• I own the copyright of the code submitted and I license it under the MIT license
• I manually tested my changes in running JabRef (always required)
• [/] I added JUnit tests for changes (if applicable)
• I added screenshots in the PR description (if change is visible to the user)
• I described the change in CHANGELOG.md in a way that is understandable for the average user (if change is visible to the user)
• I checked the user documentation: Is the information available and up to date? If not, I created an issue at https://github.com/JabRef/user-documentation/issues or, even better, I submitted a pull request updating file(s) in https://github.com/JabRef/user-documentation/tree/main/en.