[orchestrator] create separate structure for deployment and provisioning serializers
[tasks] small refactoring of deployment method
[models] add prepare_for_provisioning for cluster
[models] small refactoring, do not create network manager each time
[models] add helper offline for Node
remove skiped test
[serializers] extract serialization logic for provisioning in to separate class
[naily] fix provisioning format for naily
fix flake8
[serializer] s/get_power_pass/get_ssh_key_path/
[orchestrator] implement handlers for provisioning and deployment data
fix flake8
[tests] fix after rebase
[handlers] replace abstract method on class attribute, as we have in network_configuration
fix flake8
Merge pull request #1518 from Mirantis/custom-attributes-for-provisioning

Extract provisioning serialization to separate class