Make mw.wikibase.entity.formatPropertyValues work for non-items

To get rid of the meaningless error message this is throwing right
now and to make this compatible with having statements on non-items.

Bug: 72124
Change-Id: I8abec32dedb87f9fab78e824b3703f2f240c25b0
Merge "Make mw.wikibase.entity.formatPropertyValues work for non-items"