Fixes to integration tests in OmeroPy

This PR fixes all but 9 of the Python integration tests. Three of those fails show as passes with comments (tickets1000.py) the remainder all have either new tickets, open tickets or closed tickets that may need re-opening. All commented in the Python tab of the gdoc 'Integration Tests OMERO stable'

To run these tests there needs to be a valid user in ice.config - omero.user and omero.pass need to be set and that user created in advance of the tests. There are some performance tests that occasionally fail. 

The tests have simply been fixed to get them to pass while testing whet they are meant to test. There are still a lot of unnecessary print statements, incorrect comments and unhelpful assertions that could be improved in a tidying branch if we decide to maintain Python integration tests.

There are also some uses of BlitzGateway that should probably be moved to gateway tests rather than be exercised here in the API tests.