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
#include <key_io.h>
#include <outputtype.h>
#include <rpc/util.h>
#include <script/descriptor.h>
#include <script/signingprovider.h>
#include <tinyformat.h>
#include <util/strencodings.h>
#include <util/string.h>
#include <tuple>
InitInterfaces* g_rpc_interfaces = nullptr;
void RPCTypeCheck(const UniValue& params,