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
obj.pushKV("services", (uint64_t)addr.nServices);
        obj.pushKV("address", addr.ToStringIP());
        obj.pushKV("port", addr.GetPort());
        ret.push_back(obj);
    }
    return ret;
}
static const CRPCCommand commands[] =
{ 
  
    { "network",            "getconnectioncount",     &getconnectioncount,     {} },
    { "network",            "ping",                   &ping,                   {} },
    { "network",            "getpeerinfo",            &getpeerinfo,            {} },
    { "network",            "addnode",                &addnode,                {"node","command"} },
    { "network",            "disconnectnode",         &disconnectnode,         {"address", "nodeid"} },
    { "network",            "getaddednodeinfo",       &getaddednodeinfo,       {"node"} },
    { "network",            "getnettotals",           &getnettotals,           {} },
    { "network",            "getnetworkinfo",         &getnetworkinfo,         {} },
    { "network",            "setban",                 &setban,                 {"subnet", "command", "bantime", "absolute"} },
    { "network",            "listbanned",             &listbanned,             {} },
    { "network",            "clearbanned",            &clearbanned,            {} },
    { "network",            "setnetworkactive",       &setnetworkactive,       {"state"} },
    { "network",            "getnodeaddresses",       &getnodeaddresses,       {"count"} },
};
void RegisterNetRPCCommands(CRPCTable &t)
{
    for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++)
        t.appendCommand(commands[vcidx].name, &commands[vcidx]);
}