RPC calls ignore locktime transactions

Enable address decode and "is mine" for transactions containing the OP_CHECKLOCKTIMEVERIFY and OP_CHECKSEQUENCEVERIFY prefixes.

I'm not sure if should report something as spendable when the timelock has not yet elapsed, but we should afterward. Right now the "watch only" flag is required to see these.

Start with the RPC paths for address decoding and the "is mine" check, then trace how transactions with OP_CHECKLOCKTIMEVERIFY and OP_CHECKSEQUENCEVERIFY prefixes are handled versus watch-only transactions. Done means these transactions are recognized without the watch-only flag and are reported as spendable once their timelock has elapsed.

Written by the indexing model from the issue text.