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
{
    if (value.isNum()) {
        return {0, value.get_int64()};
    }
    if (value.isArray() && value.size() == 2 && value[0].isNum() && value[1].isNum()) {
        int64_t low = value[0].get_int64();
        int64_t high = value[1].get_int64();
        if (low > high) throw JSONRPCError(RPC_INVALID_PARAMETER, "Range specified as [begin,end] must not have begin after end");
        return {low, high};
    }
    throw JSONRPCError(RPC_INVALID_PARAMETER, "Range must be specified as end or as [begin,end]");
}
std::pair<int64_t, int64_t> ParseDescriptorRange(const UniValue& value)
{
    int64_t low, high;
    std::tie(low, high) = ParseRange(value);
    if (low < 0) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Range should be greater or equal than 0");
    }
    if ((high >> 31) != 0) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "End of range is too high");
    }
    if (high >= low + 1000000) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Range is too large");
    }
    return {low, high};
}
std::vector<CScript> EvalDescriptorStringOrObject(const UniValue& scanobject, FlatSigningProvider& provider)