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
{
            RPCHelpMan{"getnetworkinfo",
                "Returns an object containing various state info regarding P2P networking.\n",
                {},
                RPCResult{
            "{\n"
            "  \"version\": xxxxx,                      (numeric) the server version\n"
            "  \"subversion\": \"/Satoshi:x.x.x/\",     (string) the server subversion string\n"
            "  \"protocolversion\": xxxxx,              (numeric) the protocol version\n"
            "  \"localservices\": \"xxxxxxxxxxxxxxxx\", (string) the services we offer to the network\n"
            "  \"localservicesnames\": [                (array) the services we offer to the network, in human-readable form\n"
            "      \"SERVICE_NAME\",                    (string) the service name\n"
            "       ...\n"
            "   ],\n"
            "  \"localrelay\": true|false,              (bool) true if transaction relay is requested from peers\n"
            "  \"timeoffset\": xxxxx,                   (numeric) the time offset\n"
            "  \"connections\": xxxxx,                  (numeric) the number of connections\n"
            "  \"networkactive\": true|false,           (bool) whether p2p networking is enabled\n"
            "  \"networks\": [                          (array) information per network\n"
            "  {\n"
            "    \"name\": \"xxx\",                     (string) network (ipv4, ipv6 or onion)\n"
            "    \"limited\": true|false,               (boolean) is the network limited using -onlynet?\n"