The MathEntitySelector gets its config from wbRepo which caused a hard
dependency on the Wikibase client.
If the Wikibase client config is not available a default value (wikidata)
is used to determine the URL of the foreign repo.
As the dropdown will never do write operations, we restrict the repo
access to anonymous read only.
Bug: T313143
Change-Id: Iba33dfd32a78f4ad7c2e99a1f56218458ab884b4
The current wikidata entity selector requires WikibaseRepo to be enabled on the client wiki, which is only the case for very small installations.
We implement our custom entity selector that
* displays the item label and
* uses the description as tool-tip.
The implementation was inspired by
mw.widgets.TitleInputWidget.
Bug: T229939
Change-Id: I35d6cc317cf2984d9de6e062f79030f5c31c0811
