Before we can {T282999} we want to make sure everything works as intended, especially considering the codebase was fundamentally rewritten since the #wmde-techwish team created the feature.
Test plan:
[] Do the reference popups show up at all?
[] Test with an extremely long reference. The popup should have a maximum height and show a scrollbar.
[] External weblinks in the popup should open in a new browser tab.
[] Clicking a footnote marker (the [1] in the text) should jump to the bottom.
[] Does the extraction of different reference types work? (Popup shows e.g. headline "news" instead of "reference".)
[] T282999 Does the settings icon work for logged in users? (Link to configuration.)
[] Can anonymous users disable the two popup types via the settings icon?
[] Ideally check if the auto-disable feature still works when the Navigation Popups gadget is enabled. (There should never be 2 popups at the same time.)
Sources:
* https://de.wikipedia.org/wiki/Wikipedia:Technische_W%C3%BCnsche/Topw%C3%BCnsche/Vorschau_von_Einzelnachweisen_im_Artikeltext
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