When I run `scantxoutset` via RPC using big range (e.g. 10000) on XPUB, the progress report indicator (`scantxoutset status`) reports 100% at start (while the keys are being derived). This is most probably the result of the previous operation. The progress is only reset to zero when the actual scan starts. I would expect the progress is set to zero before the keys are being derived.

Output of periodic calls to `scantxoutset status` while performing long operation.

```
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 0 }
{ progress: 3 }
{ progress: 6 }
{ progress: 9 }
{ progress: 12 }
{ progress: 15 }
{ progress: 17 }
{ progress: 20 }
{ progress: 23 }
{ progress: 26 }
{ progress: 29 }
{ progress: 32 }
{ progress: 35 }
{ progress: 37 }
{ progress: 40 }
{ progress: 43 }
{ progress: 46 }
{ progress: 49 }
{ progress: 51 }
{ progress: 54 }
{ progress: 57 }
{ progress: 60 }
{ progress: 63 }
{ progress: 66 }
{ progress: 68 }
{ progress: 71 }
{ progress: 74 }
{ progress: 77 }
{ progress: 80 }
{ progress: 82 }
{ progress: 85 }
{ progress: 88 }
{ progress: 91 }
{ progress: 94 }
{ progress: 97 }
{ progress: 100 }
```
int64_t swtotal_weight = 0;
    int64_t swtxs = 0;
    int64_t total_size = 0;
    int64_t total_weight = 0;
    int64_t utxo_size_inc = 0;
    std::vector<CAmount> fee_array;
    std::vector<std::pair<CAmount, int64_t>> feerate_array;
    std::vector<int64_t> txsize_array;
    for (size_t i = 0; i < block.vtx.size(); ++i) {
        const auto& tx = block.vtx.at(i);
        outputs += tx->vout.size();
        CAmount tx_total_out = 0;
        if (loop_outputs) {
            for (const CTxOut& out : tx->vout) {
                tx_total_out += out.nValue;
                utxo_size_inc += GetSerializeSize(out, PROTOCOL_VERSION) + PER_UTXO_OVERHEAD;
            }
        }
        if (tx->IsCoinBase()) {
            continue;
        }
        inputs += tx->vin.size(); 
        total_out += tx_total_out; 
        int64_t tx_size = 0;
        if (do_calculate_size) {
            tx_size = tx->GetTotalSize();
            if (do_mediantxsize) {
                txsize_array.push_back(tx_size);
            }
            maxtxsize = std::max(maxtxsize, tx_size);