An unified interface for different wallets

[hurui200320]

Now we have two wallets as dapp API providers: WalletConnet and NeoLine. In the future, we might need to implement the O3 wallet. Each wallet has its own js API and requires a different approach to use, which introduce a lot of pain to make all of those wallet supported in the codebase.

Thus we need a unified interface for those wallets, which should have minimum features that satisfied the app's need, like sending a transaction, get a notification when tx is confirmed, etc., and some basic features, like connecting/init the wallet, reading the account address and converting into script hash, etc.

That is a scratch, we need to define each feature's interface (parameters and returned value) and behavior (when to throw what exception). Also, make sure it can be implemented by most of the wallets.