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.
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
            RPCHelpMan{"listaddressgroupings",
                "\nLists groups of addresses which have had their common ownership\n"
                "made public by common use as inputs or as the resulting change\n"
                "in past transactions\n",
                {},
                RPCResult{
            "[\n"
            "  [\n"
            "    [\n"
            "      \"address\",            (string) The bitcoin address\n"
            "      amount,                 (numeric) The amount in " + CURRENCY_UNIT + "\n"
            "      \"label\"               (string, optional) The label\n"
            "    ]\n"
            "    ,...\n"
            "  ]\n"
            "  ,...\n"
            "]\n"
                },
                RPCExamples{