Add destination addresses to listchaintxns RPC

[mlerner]

This fulfills: #416

I've broken this down into three commits:

1. Update the proto definitions to include destination addresses.
2. Implementation - Take the outputs controlled by the wallet, decode the transaction, and get the addresses that correspond to that transaction outputs pkscript. These destination addresses are then passed to the rpcserver. Additionally, rpcserver.go was updated to include the destination addresses in the TransactionDetails response.
3. Add test that checks whether the addresses stored in the wire TxOut are equal to the destination addresses.

[Roasbeef]

Thanks for the PR!

The diffs look pretty good for the most part, I especially like the decomposition of the the commits themselves. None of my comments are particularly major, so it shouldn't take long for us to get this in.

[Roasbeef]

Naming suggestion to keep things short: dest_addrs.

[Roasbeef]

The version isn't necessarily 1 (new updates use version 2 to take advantage of CSV ,etc) . Instead, you can just initialize an empty transaction like so:

wireTx := &wire.MsgTx{}

[Roasbeef]

Similar comment here w.r.t to just creating an empty transaction (though I realize now that my original code made this mistake as well).

[Roasbeef]

This could use a comment explaining that the mapping is from: blockHash -> transactionHash -> transactionOutputs.

[Roasbeef]

We typically try on a best-effort basis to wrap to 80 characters. This diff has a few offenders.

[Roasbeef]

Rather than manually comparing, you can just do reflect.DeepEqual.

[mlerner]

@Roasbeef: updated with your feedback.

[Roasbeef]

Can you rebase this, and regenerate the proto files? Thanks, they're currently conflicting as a PR went in recently which also modified the proto files.

[mlerner]

@Roasbeef: updated.

[mlerner]

Rebased again.

[Roasbeef]

LGTM 🐳