Moving common pytest fixtures, for use on both OmeroWeb and OmeroPy
linking conftest on gatewaytests to omero.gateway.pytest_fixtures
dbhelpers also grab ICE_CONFIG from environment if available
adding pytest command to web plugin
webgateway pytests
webclient pytests
webadmin pytests
pytest web plugin sets DJANGO_SETTINGS_MODULE
removing the unittest import from webadmin.tests
renaming web pytest to web test, making it consistent with omeropy tests
Removing web plugin unittest call
Retry ShareData parsing with 1.0 encoding (See #11322)

If the first attempt to parse ShareData from the database
fails (i.e. produces null), then a second attempt is made
with an Ice.Communicator instance initialized with 1.0 as
the Ice.Default.EncodingVersion value.

Note: `Ice.EncodingVersion` is not being used because it was
first introduced in 3.5 meaning that this code would not be
compilable with the other zeroc jars.
Fix NPE on bad parsing in main
Catch MarshalExceptions and return null
Move to strict version 1.0 encoding (Fix #11322)
Refactor stream creation into safe helper (Fix #11322)
Various tests for thumbnails (See #10618)
Whitespace fixes for test_thumbnailPerms.py
Cleaning testThumbs
Test ImageWrapper.getThumbnail (See #10618)

This gatewaytest goes through various combinations
of the uses of getThumbnail(). They are all currently
passing which points to 10618 actually being an API
usage issue.