[Metrics] Add CrossRef Cited-By to article detail page

[mreiko]

Description
Add CrossRef "cited-by" functionality to the article detail page. In the UI, this appears in 2 locations:

1. In the "Metrics" tab on the article detail page
   Example: from live ORE ENOVAT: the European Network for Optimization of Veterinary Antimicrobial Treatment:

We would duplicate this design and functionality for CrossRef only; however, we would not have a logo but instead, we'd list "CrossRef" with the # of citations under the title "Cited", and the modal would appear on click.

2. In the article page side bar under "Metrics"

Draft PRs
crossref-ojs: pkp/crossref-ojs#108
pkp-lib: pkp/pkp-lib#13292
ui-library: pkp/ui-library#980
ore-theme: https://github.com/pkp/oreTheme/pull/55
ojs: pkp/ojs#5810

[mreiko]

hi @bozana would you please verify that the scope is correct?

[bozana]

see pkp/pkp-lib#13221 for implementation details

[mreiko]

Hi @taslangraham Can this one be completed this week and submitted to QA for testing?

[taslangraham]

Hi @taslangraham Can this one be completed this week and submitted to QA for testing?

I'll have the PRs ready for review this week. Once review is completed, it can move over to QA.

[taslangraham]

@bozana, this is ready for review. PRs are listed at #316 (comment). Below are a few example screenshots of the feature. Once everything looks good, I'll port this to crossref-ops.

1. Settings to enabled Cited-by (Settings -> Distribution -> DOIs -> Registration -> Enable Cited-by)

2. Cited-by under the metrics tab

3. Modal listing all citations

3.a Example text produced when Copy Citation Details button is clicked on modal

1 10.1007/978-3-031-47655-6_26 https://doi.org/10.1007/978-3-031-47655-6_26 Interactive Storytelling Lecture Notes in Computer Science 2023 14383 Bitter Jessica L., Kräuter Noura, Spierling Ulrike
2 10.1145/3701571.3701601 https://doi.org/10.1145/3701571.3701601 Proceedings of the International Conference on Mobile and Ubiquitous Multimedia 2024 Kunzová Nikola, Štěpánek Adam, Echeverri Daniel, K. Langlois Danielle, Kriglstein Simone
3 10.1007/s12136-026-00674-6 https://doi.org/10.1007/s12136-026-00674-6 3 Fiction, Identity, and Existence: A Study in Experimental Philosophy Acta Analytica 2026 41 Favazzo Jansan, Burro Roberto

4. Citations count under metrics section of Article tab