Bugfix: XML Repository Behaved Differently for ContentType#getDirectInstances()

When setting up tests with the XML repository, the implementations of ContentType#getDirectInstances() and QueryService#poseContentQuery(...) could deliver different results as in a real Content Server connection. While the real connection always delivers all contents regardless of user's rights on them, the XML repository would filter them for readability by the current UAPI user. This deviation is now fixed and the XML repository behaves just like the real connection.

Follow Section, “Bugfix: XML Repository Behaved Differently for ContentType#getDirectInstances()” for upgrade information.

(CMS-29959)