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
for (const auto& i : stats.mapSendBytesPerMsgCmd) {
            if (i.second > 0)
                sendPerMsgCmd.pushKV(i.first, i.second);
        }
        obj.pushKV("bytessent_per_msg", sendPerMsgCmd);
        UniValue recvPerMsgCmd(UniValue::VOBJ);
        for (const auto& i : stats.mapRecvBytesPerMsgCmd) {
            if (i.second > 0)
                recvPerMsgCmd.pushKV(i.first, i.second);
        }
        obj.pushKV("bytesrecv_per_msg", recvPerMsgCmd);
        ret.push_back(obj);
    }
    return ret;
}
static UniValue addnode(const JSONRPCRequest& request)
{
    std::string strCommand;
    if (!request.params[1].isNull())
        strCommand = request.params[1].get_str();
    if (request.fHelp || request.params.size() != 2 ||
        (strCommand != "onetry" && strCommand != "add" && strCommand != "remove"))
        throw std::runtime_error(
            RPCHelpMan{"addnode",
                "\nAttempts to add or remove a node from the addnode list.\n"
                "Or try a connection to a node once.\n"
                "Nodes added using addnode (or -connect) are protected from DoS disconnection and are not required to be\n"
                "full nodes/support SegWit as other outbound peers are (though such peers will not be synced from).\n",
                {
                    {"node", RPCArg::Type::STR, RPCArg::Optional::NO, "The node (see getpeerinfo for nodes)"},