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
{
    std::string desc_str;
    std::pair<int64_t, int64_t> range = {0, 1000};
    if (scanobject.isStr()) {
        desc_str = scanobject.get_str();
    } else if (scanobject.isObject()) {
        UniValue desc_uni = find_value(scanobject, "desc");
        if (desc_uni.isNull()) throw JSONRPCError(RPC_INVALID_PARAMETER, "Descriptor needs to be provided in scan object");
        desc_str = desc_uni.get_str();
        UniValue range_uni = find_value(scanobject, "range");
        if (!range_uni.isNull()) {
            range = ParseDescriptorRange(range_uni);
        }
    } else {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Scan object needs to be either a string or an object");
    }
    std::string error;
    auto desc = Parse(desc_str, provider, error);
    if (!desc) {
        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
    }