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 }
```
{
    std::unique_ptr<CCoinsViewCursor> pcursor;
    CCoinsStats stats{CoinStatsHashType::NONE};
    CBlockIndex* tip;
    {
        
        
        
        
        
        
        
        
        
        
        
        
        LOCK(::cs_main);
        chainstate.ForceFlushStateToDisk();
        if (!GetUTXOStats(&chainstate.CoinsDB(), chainstate.m_blockman, stats, node.rpc_interruption_point)) {
            throw JSONRPCError(RPC_INTERNAL_ERROR, "Unable to read UTXO set");
        }
        pcursor = chainstate.CoinsDB().Cursor();
        tip = chainstate.m_blockman.LookupBlockIndex(stats.hashBlock);
        CHECK_NONFATAL(tip);
    }
    SnapshotMetadata metadata{tip->GetBlockHash(), stats.coins_count, tip->nChainTx};
    afile << metadata;
    COutPoint key;