MobileFrontend can show nice article taglines (can be enabled by MFDisplayWikibaseDescriptions) . Sadly, this feature causes a hard dependency on WikiBase, and maitenance cost, as MobileFrontend has to know how to build Wikibase entities. It's not MobileFrontend reponsibility, thus should be removed from MobileFrontend codebase.

Acceptance Criteria

• Article tagline is set up by the hook. MobileFrontendHooks::findTagLine should run a new hook.
• Wikibase Client runs the hook to fill the Article tagline
• ExtMobileFrontend::getWikibaseEntity() and ExtMobileFrontend::getWikibaseDescription() should be removed

Open questions

• Should we rename the MFDisplayWikibaseDescriptions config?
• Should we rename MobileContext:shouldShowWikibaseDescriptions() method?

Developer notes:

Proposed Hook name: MobileFrontendFetchArticleTagline

The best place to call the hook most probably is the SkinMinerva::getTaglineHtml() - we could abandon the wgMFDescription variable.
This would not only untagle MobileFrontend and Wikibase, but also remove one dependency between MobileFrontend and Minvera