Add help icon/link to constraint reports

Authored by Lucas_Werkmeister_WMDE on Fri, May 19, 4:09 PM.

Description

Add help icon/link to constraint reports

The link points to the constraint type’s subpage of the Property
constraints portal on Wikidata.

Change-Id: Icced3d6624f8eb2059bd71e9fb2df372924ca46f