* Added missing out modifier to UpgradedContract class
* Added ContractUpgradeFlow.Instigator to whitelist in AbstractNode
* Added test for contract upgrade using RPC
* Add support for contract upgrades
* Add interface for the upgraded contract to implement, which provides functionality for upgrading legacy states.
* Add shared upgrade command and verification code for it.
* Add DummyContractV2 to illustrate what an upgraded contract looks like.
* Add new functions to vault service to support upgrading state objects.
* Add contract upgrade flow
