Add unit tests for switch workflows

gso/workflows/__init__.py

gso/workflows/switch/create_switch.py

gso/workflows/switch/terminate_switch.py

gso/workflows/switch/validate_switch.py

test/workflows/edge_port/test_create_edge_port.py

test/workflows/iptrunk/test_create_iptrunk.py

.../nren_l3_core_service/test_create_nren_l3_core_service.py

test/workflows/router/test_modify_connection_strategy.py

test/workflows/site/test_create_site.py

test/workflows/site/test_modify_site.py

test/workflows/site/test_terminate_site.py

test/workflows/switch/__init__.py

test/workflows/switch/test_activate_switch.py

test/workflows/switch/test_create_imported_switch.py

test/workflows/switch/test_create_switch.py

test/workflows/switch/test_import_switch.py

test/workflows/switch/test_terminate_switch.py

test/workflows/switch/test_validate_switch.py

test/workflows/tasks/test_task_validate_products.py