add moodi start and stop steps

gso/oss-params-example.json

gso/settings.py

gso/utils/workflow_steps.py

gso/workflows/iptrunk/create_iptrunk.py

gso/workflows/iptrunk/deploy_twamp.py

gso/workflows/iptrunk/migrate_iptrunk.py

gso/workflows/iptrunk/modify_isis_metric.py

gso/workflows/iptrunk/modify_trunk_interface.py

gso/workflows/iptrunk/terminate_iptrunk.py

gso/workflows/iptrunk/validate_iptrunk.py

gso/workflows/router/promote_p_to_pe.py

gso/workflows/router/terminate_router.py

gso/workflows/router/update_ibgp_mesh.py

gso/workflows/router/validate_router.py