Currently the `getnetworkinfo` returns something like: 

```
"localservices": "0000000000000449",
```

Manually parsing this consistently gives me a headache (see also https://github.com/sipa/bitcoin-seeder/pull/77).

It would be useful to parse this and show the right combination of `NODE_NETWORK`, `NODE_GETUTXO`, `NODE_BLOOM`, `NODE_WITNESS`, `NODE_NETWORK_LIMITED` and `NODE_COMPACT_FILTERS`. In addition the help text for `getnetworkinfo` could be expanded to mention the right BIP numbers for known flags.

There is some ad hoc parsing to populate e.g. `localrelay`, etc (?).  Their help text could also refer back to `NODE_GETUTXO`.

See also: https://en.bitcoin.it/wiki/Protocol_documentation#Network_address
{
    return boost::apply_visitor(DescribeAddressVisitor(), dest);
}
unsigned int ParseConfirmTarget(const UniValue& value, unsigned int max_target)
{
    int target = value.get_int();
    if (target < 1 || (unsigned int)target > max_target) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid conf_target, must be between %u - %u", 1, max_target));
    }
    return (unsigned int)target;
}
RPCErrorCode RPCErrorFromTransactionError(TransactionError terr)
{
    switch (terr) {
        case TransactionError::MEMPOOL_REJECTED:
            return RPC_TRANSACTION_REJECTED;
        case TransactionError::ALREADY_IN_CHAIN:
            return RPC_TRANSACTION_ALREADY_IN_CHAIN;
        case TransactionError::P2P_DISABLED:
            return RPC_CLIENT_P2P_DISABLED;
        case TransactionError::INVALID_PSBT:
        case TransactionError::PSBT_MISMATCH:
            return RPC_INVALID_PARAMETER;
        case TransactionError::SIGHASH_MISMATCH:
            return RPC_DESERIALIZATION_ERROR;
        default: break;
    }
    return RPC_TRANSACTION_ERROR;
}
UniValue JSONRPCTransactionError(TransactionError terr, const std::string& err_string)