ckb-testtool enhanchment

[jjyr]

Chain simulator

• Provide a function to set up a devnet chain, including built-in contracts and the genesis block.
• Provide a high-level interface of the dev-chain to replace the Context.

Helper functions

• Prepare the address with CKB for testing.
• Signer abstraction(single lock, multi-sig lock, rc lock).
• Automatically complete the transaction inputs with a sender address.

Debugger

• Support easily build & export a ckb-debugger format transaction

[blckngm]

Copying/editing from #88:

I think we should try to make it easier to debug/profile transactions from ckb-testtool, e.g. we can add a function to dump a transaction in the format expected by ckb-debugger.

[jjyr]

After second thoughts, I think we should focus on implementing a CKB RPC-compatible simulator chain instead of providing more testing helper functions.

Compared to the CKB dev chain, we should have the advantage in the following aspects:

1. Easily mock cells and blocks to simulate different scenarios.
2. Record failed transactions and provide a way to replay them.
3. Output diagnosis for failed transactions.
4. Support different submit modes.

Other Dapp developers can connect to the simulator chain to debug their Apps without any modification.