The new `getrpcinfo` shows a list of the active commands and the duration each command has been running. This sounds like a good place to report a completion percentage for any command doing a blockchain rescan, to solve [this problem](https://bitcoin.stackexchange.com/q/83236/90721).
"\nAs a JSON-RPC call\n"
            + HelpExampleRpc("listtransactions", "\"*\", 20, 100")
                },
            }.ToString());
    
    
    pwallet->BlockUntilSyncedToCurrentChain();
    const std::string* filter_label = nullptr;
    if (!request.params[0].isNull() && request.params[0].get_str() != "*") {
        filter_label = &request.params[0].get_str();
        if (filter_label->empty()) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Label argument must be a valid label name or \"*\".");
        }
    }
    int nCount = 10;
    if (!request.params[1].isNull())
        nCount = request.params[1].get_int();
    int nFrom = 0;
    if (!request.params[2].isNull())
        nFrom = request.params[2].get_int();
    isminefilter filter = ISMINE_SPENDABLE;
    if(!request.params[3].isNull())
        if(request.params[3].get_bool())
            filter = filter | ISMINE_WATCH_ONLY;
    if (nCount < 0)
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative count");
    if (nFrom < 0)
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative from");
    UniValue ret(UniValue::VARR);
    {