Improve native contract update mechanism

[AnnaShaleva]

Summary or problem description
Native contract update mechanism introduced in #2942 allows to enable new methods and events starting from some hardfork, and it's good. However, we're missing the following functionality:

• update method's signature (change the parameters name, add/remove parameters from method) without introducing new method
• update event's name or parameter list starting from some hardfork
• exclude method/event starting from some hardfork
• destroy native contract

Without this functionality implemented, changes like #3209 will inevitably require node resync, so we consider this functionality a useful one.

Do you have any solution you want to propose?
Almost all cases may be solved with ActiveTill field added to the native contract/method/event. The handler logic for this field should be similar to the logic of the following fields (with single adjustment: ActiveTill prevents contract/method/event from being active):

neo/src/Neo/SmartContract/Native/NativeContract.cs

Line 121 in 429a081

public virtual Hardfork? ActiveIn { get; } = null;

neo/src/Neo/SmartContract/Native/ContractMethodAttribute.cs

Line 25 in 429a081

public Hardfork? ActiveIn { get; init; } = null;

neo/src/Neo/SmartContract/Native/ContractEventAttribute.cs

Line 24 in 429a081

public Hardfork? ActiveIn { get; init; } = null;

Another option was suggested by @roman-khimov (correct me, if I'm wrong, please): we may have a set of separate classes for every version of native contract. Starting from every hardfork, a specific version of the contract should be used (if specified).

Where in the software does this update applies to?

• Native contracts

[shargon]

I think that we can add it when needed

[AnnaShaleva]

A part of this issue (methods' "active till") is implemented in the #3234. We need to implement events' "active till" (ref. #3234 (comment)) and improve ContractMethodAttribute constructor (ref. #3234 (comment)).