PR #16866 renamed the `decode` argument in gettransaction to `verbose` to make it more consistent with other RPC calls like getrawtransaction.

However, if I understand correctly, it inadvertently overloaded the "details" fields when `verbose` is passed.

The result is that the original "details" field is no longer returned correctly, which seems to be a breaking API change.
RPCExamples{
            "\nList all labels\n"
            + HelpExampleCli("listlabels", "") +
            "\nList labels that have receiving addresses\n"
            + HelpExampleCli("listlabels", "receive") +
            "\nList labels that have sending addresses\n"
            + HelpExampleCli("listlabels", "send") +
            "\nAs a JSON-RPC call\n"
            + HelpExampleRpc("listlabels", "receive")
                },
            }.Check(request);
    LOCK(pwallet->cs_wallet);
    std::string purpose;
    if (!request.params[0].isNull()) {
        purpose = request.params[0].get_str();
    }
    
    std::set<std::string> label_set;
    for (const std::pair<const CTxDestination, CAddressBookData>& entry : pwallet->mapAddressBook) {
        if (purpose.empty() || entry.second.purpose == purpose) {
            label_set.insert(entry.second.name);
        }
    }
    UniValue ret(UniValue::VARR);
    for (const std::string& name : label_set) {
        ret.push_back(name);
    }
    return ret;
}
UniValue sethdseed(const JSONRPCRequest& request)