As a user I can filter, via a JQL Function, all Test Set that have *all its Tests* in a TP

As a user I can filter, via JQL Function, all Test Set that have all its Tests in a TP

issuetype = "Test Set" and issue in testSetFullyIn("TP")

It may make sense to accept a list of TPs in order to see if the Test Set Tests are associated with multiple Test Plans.