Display the services proper display name in ambiguous relation dialogs
Split up the ambiguousAddRelationCheck method to make it easier to test
Added missing ambiguous relation tests and tests for new naming functionality
Merge pull request #636 from hatched/relation-selector

Ambiguous relation dialog should use real display names for ghost services

The ambiguous relation dialog was using the service names even if the name was a ghost service id. This branch adds a `displayName` property and missing tests for the ambiguous relation UI code.