Improve createTestContext in debugger

[XuJiandong]

Replace mockOutPoint with real life OutPoint in testnet/mainnet. For well known scripts, they are always the same and can be hard coded.

[homura]

It's a cool idea. For Lumos to achieve this, we'll need to change the hash_type to type in createTestContext.

However, I must admit that things are a bit hectic over here at the moment, so we might not be able to implement it as soon as we'd like.

[XuJiandong]

Improve it if you have time. It's not an urgent feature.

My initial requirement is to make it possible to dump transaction before going to p2p network. For transactions already confirmed, we have ckb-transaction-dumper. But for these failed transactions, currently, we don't have any tool.