adding listOrphans to BlitzGateway, see #11413
moving listOrphans to BlitzGateway, close #11413
fixing illegal query, close #11422
fixing spelling mistake
removing unused line
adding test for listOrphans, see #11413
Merge pull request #1544 from aleksandra-tarkowska/rebased/develop/listOrphans_11413

List orphans 11413 (rebased onto develop)