Add support for this constraint type: https://www.wikidata.org/wiki/Q52712340

Essentially, some properties have qualifiers that they use but which only have a few valid values. For example, a video game store that only supports Windows, macOS, and Linux - but which uses platform qualifiers to show which a given game supports - should not allow the value "Nintendo Wii" in that qualifier. This constraint qualifier would be about warning the user if they use a value that isn't in the configured list for the given qualifier on that property.