wikipedia: retrieve image descriptions for non-fragment links to Wikipedia/Wikimedia Commons files

[SnoopJ]

Requested Feature

Sopel should be able to retrieve the file description in response to links directly to File:… objects (i.e. links that are not fragments of the form Some_Other_Article#/media/File:…)

Currently, Sopel responds to these links in a generic way using the url plugin, because URLs containing File: are excluded by the wikipedia plugin's pattern.

<SnoopJ> https://commons.wikimedia.org/wiki/File:Comparison_strut_diffraction_spikes.svg
<Sopel> [url] File:Comparison strut diffraction spikes.svg - Wikimedia Commons | commons.wikimedia.org
<SnoopJ> https://en.wikipedia.org/wiki/File:Staring_Down_Hurricane_Florence.jpg
<Sopel> [url] File:Staring Down Hurricane Florence.jpg - Wikipedia | en.wikipedia.org

With this feature implemented, the responses will come from the wikipedia plugin and will include the file description if there is one, something akin to the behavior under #2388 but not restricted to fragments at the end of an article URL

17:31 <SnoopJ> https://commons.wikimedia.org/wiki/File:Comparison_strut_diffraction_spikes.svg
17:31 <Sopel> [wikipedia] Comparison of diffraction spikes for various strut arrangements of a reflecting telescope. The inner circle represents the secondary mirror.
17:31 <SnoopJ> https://en.wikipedia.org/wiki/File:Staring_Down_Hurricane_Florence.jpg
17:31 <Sopel> [wikipedia] Photo taken of Hurricane Florence convection with deep eyewall in Atlantic Sea from ISS by astronaut Alexander Gerst: Ever stared down the gaping eye of a category 4 hurricane? It's chilling, even from space ...(There is hope, photos and observations like that can improve preparations for hurricanes like Hurricane Florence.)

Problems Solved

This feature request is an extension of the functionality added by #2388

Alternatives

No response

Notes

Here are some test URLs that may be helpful for checking the functionality of this feature

https://en.wikipedia.org/wiki/File:Staring_Down_Hurricane_Florence.jpg
https://en.wikipedia.org/wiki/File:Google1998.png
https://en.wikipedia.org/wiki/History_of_supercomputing#/media/File:Paragon_XP-E_-_mesh.jpg
https://ja.wikipedia.org/wiki/スーパーコンピュータ技術史#/media/ファイル:CDC_6600_introduced_in_1964.jpg
https://de.wikipedia.org/wiki/Liste_der_Stra%C3%9Fen_in_Aachen-Mitte#/media/Datei:Aachen-Mitte.jpg
https://commons.wikimedia.org/wiki/File:Comparison_strut_diffraction_spikes.svg