Lists retracted articles on the author aspect

[egonw]

Fixes #2521

Description

This patch adds a conditional section to the /author/ aspect. If the author is author of retracted articles, then a 'number of retracted articles' and table with the retracted article gets added to the page. If there are none, nothing is shown.

Testing

Please describe the tests that you ran to verify your changes. Provide instructions, so we can reproduce. Please also list any relevant details for your test configuration.

• Author without retractions: http://127.0.0.1:8100/author/Q20895241
• Author with retractions: http://127.0.0.1:8100/author/Q1545025#list-of-retracted-articles

In the latter case, something like this should be visible on the page:

Checklist

• [ ] I have commented my code, particularly in hard-to-understand areas
• [x] My changes generate no new warnings
• [x] I have not used code from external sources without attribution
• [ ] I have considered accessibility in my implementation
• [x] There are no remaining debug statements (print, console.log, ...)

[fnielsen]

For an overview of retracted articles see also https://synia.toolforge.org/#retraction

[fnielsen]

PR is running now, e.g., https://scholia.toolforge.org/author/Q58632#list-of-retracted-articles