Citizen allows stored XSS in Command Palette tip messages

Citizen is a MediaWiki skin that makes extensions part of the cohesive experience. Multiple system messages are inserted into the CommandPaletteFooter as raw HTML, allowing anybody who can edit those messages to insert arbitrary HTML into the DOM. This impacts wikis where a group has the `editinterface` but not the `editsitejs` user right. This vulnerability is fixed in 3.3.1.