Template to display an icon with a tooltip such as "Edit this at Wikidata".
Icon will be linked to the Wikidata entry for the article where this is placed.
The link can be modified to point to a specific property (or part thereof) in the Wikidata entry by supplying the optional named parameter |pid=.
This message is only displayed if parameter |1=} is empty; i.e. when called from within a template, it can be coded not to display the icon, which means the value from Wikidata is not used.
The Wikidata ID can optionally be supplied for testing outside the article (this is an expensive call).
