StateService: broken findstates handler in case of destroyed/updated contract

[AnnaShaleva]

Describe the bug
The new findstates RPC API introduced in #638 seems to be broken. The reason is in this and this lines of the method. findstates tries GetProof for historical state, but GetProof asks ContractManagement for the contract ID. As a result, for those contracts that have been destroyed and for the historical states of that contracts findstates will throw an exception, because ContractManagement is not able to get historical contract ID of destroyed contract.

Expected behavior
findstates should get historical proof, i.e. fetch historical contract ID from MPT (using GetHistoricalContractState method) to get proof for the first and the last states.

Platform:

• Version: StateService, current master (606bd27).

[AnnaShaleva]

The same problem may happen while trying to find the historical states of the updated contract if its hash has been changed.

[cloud8little]

The same problem may happen while trying to find the historical states of the updated contract if its hash has been changed.

N3 will not change the contract hash when update.

[ZhangTao1596]

We should use GetHistoricalContractState.

[AnnaShaleva]

The same problem may happen while trying to find the historical states of the updated contract if its hash has been changed.

N3 will not change the contract hash when update.

Thank you, forgot about it. Then the issue is relevant for destroyed contracts only.