SHACL - Validating maxCount/minCount across union of graphs with duplicates

[hmottestad]

Validating maxCount/minCount for a single graph always guarantees that there are no duplicates since a quad is unique.

When validating the union of multiple graphs it becomes possible to have the same value in more than one graph. This seems like undefined behaviour in the SHACL spec.

We decide that maxCount and minCount will work on the set of values. If one or more graph contain the same value then this value will only be counted once.