[WIP] Extract PDF References

[aqurilla]

This fixes #10200 by implementing reference extraction from PDF files

Mandatory checks

• [ ] Change in CHANGELOG.md described in a way that is understandable for the average user (if applicable)
• [ ] Tests created for changes (if applicable)
• [ ] Manually tested changed features in running JabRef (always required)
• [ ] Screenshots added in PR description (for UI changes)
• [ ] Checked developer's documentation: Is the information available and up to date? If not, I outlined it in this pull request.
• [ ] Checked 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 to the documentation repository.

[koppor]

I added an initial test pdf at https://github.com/aqurilla/jabref/pull/1.

[BBC-Esq]

Interested in this as an attorney and extracting numerous legal citations...

[koppor]

Interested in this as an attorney and extracting numerous legal citations...

Can you share example PDFs we can license under MIT license - or maybe just sharable under a different license. 😅

[koppor]

Screenshots:

1. Activate functionality

2. Result

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For completeness, the PDF part with references:

[koppor]

@aqurilla Very nice work! Thank you for working on this!. Sorry on us for not having given feedback earlier.

[aqurilla]

@koppor no problem, thank you!

[koppor]

@koppor no problem, thank you!

@aqurilla Just as side note: I implement the offline parsing at https://github.com/JabRef/jabref/pull/11156. Thanks to your "Framework", I could focus on the logic part!

[aqurilla]

@koppor that is great to hear! Thanks for adding the offline functionality for this feature