tests: Fix test failures for Local storage and Basic (SG) zones
* Skip migrate vm when localstorage enabled
* Fix test_direct_download.py
* Skip test_03_create_network_domain_network_offering in basic zones
* Skip test_03_create_vpc_domain_vpc_offering in basic zones
* Skip test_01_add_primary_storage_disabled_host if localstorageenabled
This PR prepares marvin and tests for python3. it was part of #4479, until nose2 was decided to be abandoned from that PR.
Re-PR of #4543 and #3730 to enable cooperation
Co-authored-by: Daan Hoogland <dahn@onecht.net>
Co-authored-by: Gabriel Beims Bräscher <gabriel@apache.org>
Co-authored-by: Rohit Yadav <rohit.yadav@shapeblue.com>
